diff --git a/rules/sort-classes-utils.ts b/rules/sort-classes-utils.ts
index fcc0f5868..432bb0e4e 100644
--- a/rules/sort-classes-utils.ts
+++ b/rules/sort-classes-utils.ts
@@ -9,6 +9,8 @@ import type {
 } from './sort-classes.types'
 import type { CompareOptions } from '../utils/compare'
 
+import { validateNoDuplicatedGroups } from '../utils/validate-groups-configuration'
+import { allModifiers, allSelectors } from './sort-classes.types'
 import { matches } from '../utils/matches'
 
 interface CustomGroupMatchesProps {
@@ -72,7 +74,7 @@ export const generateOfficialGroups = (
 /**
  * Get possible combinations of n elements from an array
  */
-const getCombinations = (array: string[], n: number): string[][] => {
+export const getCombinations = (array: string[], n: number): string[][] => {
   let result: string[][] = []
 
   let backtrack = (start: number, comb: string[]) => {
@@ -253,3 +255,47 @@ export const getCompareOptions = (
     ignoreCase: options.ignoreCase,
   }
 }
+
+export let validateGroupsConfiguration = (
+  groups: Required<SortClassesOptions[0]>['groups'],
+  customGroups: Required<SortClassesOptions[0]>['customGroups'],
+): void => {
+  let availableCustomGroupNames = Array.isArray(customGroups)
+    ? customGroups.map(customGroup => customGroup.groupName)
+    : Object.keys(customGroups)
+  let invalidGroups = groups
+    .flat()
+    .filter(
+      group =>
+        !isPredefinedGroup(group) && !availableCustomGroupNames.includes(group),
+    )
+  if (invalidGroups.length) {
+    throw new Error('Invalid group(s): ' + invalidGroups.join(', '))
+  }
+  validateNoDuplicatedGroups(groups)
+}
+
+const isPredefinedGroup = (input: string): boolean => {
+  if (input === 'unknown') {
+    return true
+  }
+  let singleWordSelector = input.split('-').at(-1)
+  if (!singleWordSelector) {
+    return false
+  }
+  let twoWordsSelector = input.split('-').slice(-2).join('-')
+  let isTwoWordSelectorValid = allSelectors.includes(
+    twoWordsSelector as Selector,
+  )
+  if (
+    !allSelectors.includes(singleWordSelector as Selector) &&
+    !isTwoWordSelectorValid
+  ) {
+    return false
+  }
+  let modifiers = input.split('-').slice(0, isTwoWordSelectorValid ? -2 : -1)
+  return (
+    new Set(modifiers).size === modifiers.length &&
+    modifiers.every(modifier => allModifiers.includes(modifier as Modifier))
+  )
+}
diff --git a/rules/sort-classes.ts b/rules/sort-classes.ts
index 8ec4d3523..261c5db30 100644
--- a/rules/sort-classes.ts
+++ b/rules/sort-classes.ts
@@ -9,6 +9,7 @@ import type {
 import type { SortingNodeWithDependencies } from '../utils/sort-nodes-by-dependencies'
 
 import {
+  validateGroupsConfiguration,
   getOverloadSignatureGroups,
   generateOfficialGroups,
   customGroupMatches,
@@ -243,6 +244,8 @@ export default createEslintRule<SortClassesOptions, MESSAGE_ID>({
           order: 'asc',
         } as const)
 
+        validateGroupsConfiguration(options.groups, options.customGroups)
+
         let sourceCode = getSourceCode(context)
         let className = node.parent.id?.name
 
diff --git a/test/sort-classes-utils.test.ts b/test/sort-classes-utils.test.ts
index e98fabf57..f879fadfb 100644
--- a/test/sort-classes-utils.test.ts
+++ b/test/sort-classes-utils.test.ts
@@ -1,6 +1,11 @@
 import { describe, expect, it } from 'vitest'
 
-import { generateOfficialGroups } from '../rules/sort-classes-utils'
+import {
+  validateGroupsConfiguration,
+  generateOfficialGroups,
+  getCombinations,
+} from '../rules/sort-classes-utils'
+import { allModifiers, allSelectors } from '../rules/sort-classes.types'
 
 describe('sort-classes-utils', () => {
   it('sort-classes-utils: should generate official groups', () => {
@@ -44,4 +49,84 @@ describe('sort-classes-utils', () => {
       'method',
     ])
   })
+
+  describe('validateGroupsConfiguration', () => {
+    it('allows predefined groups', () => {
+      let allModifierCombinationPermutations =
+        getAllNonEmptyCombinations(allModifiers)
+      let allPredefinedGroups = allSelectors
+        .map(selector =>
+          allModifierCombinationPermutations.map(
+            modifiers => `${modifiers.join('-')}-${selector}`,
+          ),
+        )
+        .flat()
+        .concat(allSelectors)
+      expect(
+        validateGroupsConfiguration(allPredefinedGroups, []),
+      ).toBeUndefined()
+    })
+
+    it('allows custom groups with the new API', () => {
+      expect(
+        validateGroupsConfiguration(
+          ['static-property', 'myCustomGroup'],
+          [
+            {
+              groupName: 'myCustomGroup',
+            },
+          ],
+        ),
+      ).toBeUndefined()
+    })
+
+    it('throws an error with predefined groups with duplicate modifiers', () => {
+      expect(() =>
+        validateGroupsConfiguration(['static-static-property'], []),
+      ).toThrow('Invalid group(s): static-static-property')
+    })
+
+    it('throws an error if a duplicate group is provided', () => {
+      expect(() =>
+        validateGroupsConfiguration(['static-property', 'static-property'], []),
+      ).toThrow('Duplicated group(s): static-property')
+    })
+
+    it('throws an error if invalid groups are provided with the new API', () => {
+      expect(() =>
+        validateGroupsConfiguration(
+          ['static-property', 'myCustomGroup', ''],
+          [
+            {
+              groupName: 'myCustomGroupNotReferenced',
+            },
+          ],
+        ),
+      ).toThrow('Invalid group(s): myCustomGroup')
+    })
+
+    it('allows groups with the old API', () => {
+      expect(
+        validateGroupsConfiguration(['static-property', 'myCustomGroup'], {
+          myCustomGroup: 'foo',
+        }),
+      ).toBeUndefined()
+    })
+
+    it('throws an error if invalid custom groups are provided with the old API', () => {
+      expect(() =>
+        validateGroupsConfiguration(['static-property', 'myCustomGroup'], {
+          myCustomGroupNotReferenced: 'foo',
+        }),
+      ).toThrow('Invalid group(s): myCustomGroup')
+    })
+  })
 })
+
+const getAllNonEmptyCombinations = (array: string[]): string[][] => {
+  let result: string[][] = []
+  for (let i = 1; i < array.length; i++) {
+    result = [...result, ...getCombinations(array, i)]
+  }
+  return result
+}
diff --git a/test/validate-groups-configuration.test.ts b/test/validate-groups-configuration.test.ts
index 22b43258a..7456e713a 100644
--- a/test/validate-groups-configuration.test.ts
+++ b/test/validate-groups-configuration.test.ts
@@ -21,4 +21,14 @@ describe('validate-groups-configuration', () => {
       )
     }).toThrow('Invalid group(s): invalidGroup1, invalidGroup2')
   })
+
+  it('throws an error when a duplicate group is provided', () => {
+    expect(() => {
+      validateGroupsConfiguration(
+        ['predefinedGroup', 'predefinedGroup'],
+        ['predefinedGroup'],
+        [],
+      )
+    }).toThrow('Duplicated group(s): predefinedGroup')
+  })
 })
diff --git a/utils/validate-groups-configuration.ts b/utils/validate-groups-configuration.ts
index a8d692b7a..60265dcde 100644
--- a/utils/validate-groups-configuration.ts
+++ b/utils/validate-groups-configuration.ts
@@ -1,3 +1,9 @@
+/**
+ * Throws an error if one of the following conditions is met:
+ * - One or more groups specified in `groups` are not predefined nor specified
+ * in `customGroups`
+ * - A group is specified in `groups` more than once
+ */
 export let validateGroupsConfiguration = (
   groups: (string[] | string)[],
   allowedPredefinedGroups: string[],
@@ -13,4 +19,20 @@ export let validateGroupsConfiguration = (
   if (invalidGroups.length) {
     throw new Error('Invalid group(s): ' + invalidGroups.join(', '))
   }
+  validateNoDuplicatedGroups(groups)
+}
+
+/**
+ * Throws an error if a group is specified more than once
+ */
+export let validateNoDuplicatedGroups = (
+  groups: (string[] | string)[],
+): void => {
+  let flattenGroups = groups.flat()
+  let duplicatedGroups = flattenGroups.filter(
+    (group, index) => flattenGroups.indexOf(group) !== index,
+  )
+  if (duplicatedGroups.length) {
+    throw new Error('Duplicated group(s): ' + duplicatedGroups.join(', '))
+  }
 }