diff --git a/ext/js/pages/settings/dictionary-import-controller.js b/ext/js/pages/settings/dictionary-import-controller.js
index 1c1b7720c4..12fb5a4bb8 100644
--- a/ext/js/pages/settings/dictionary-import-controller.js
+++ b/ext/js/pages/settings/dictionary-import-controller.js
@@ -176,8 +176,20 @@ export class DictionaryImportController {
             return;
         }
 
+        const installedDictionaries = await this._settingsController.getDictionaryInfo();
+        /** @type {Set<string>} */
+        const installedDictionaryNames = new Set();
+        /** @type {Set<string>} */
+        const installedDictionaryDownloadUrls = new Set();
+        for (const dictionary of installedDictionaries) {
+            installedDictionaryNames.add(dictionary.title);
+            if (dictionary.downloadUrl) {
+                installedDictionaryDownloadUrls.add(dictionary.downloadUrl);
+            }
+        }
+
         for (const {property, element} of recommendedDictionaryCategories) {
-            this._renderRecommendedDictionaryGroup(recommendedDictionaries[language][property], element);
+            this._renderRecommendedDictionaryGroup(recommendedDictionaries[language][property], element, installedDictionaryNames, installedDictionaryDownloadUrls);
         }
 
         /** @type {NodeListOf<HTMLElement>} */
@@ -191,8 +203,10 @@ export class DictionaryImportController {
      *
      * @param {import('dictionary-recommended.js').Dictionary[]} recommendedDictionaries
      * @param {HTMLElement} dictionariesList
+     * @param {Set<string>} installedDictionaryNames
+     * @param {Set<string>} installedDictionaryDownloadUrls
      */
-    _renderRecommendedDictionaryGroup(recommendedDictionaries, dictionariesList) {
+    _renderRecommendedDictionaryGroup(recommendedDictionaries, dictionariesList, installedDictionaryNames, installedDictionaryDownloadUrls) {
         const dictionariesListParent = dictionariesList.parentElement;
         dictionariesList.innerHTML = '';
         for (const dictionary of recommendedDictionaries) {
@@ -202,7 +216,9 @@ export class DictionaryImportController {
                 }
                 const template = this._settingsController.instantiateTemplate('recommended-dictionaries-list-item');
                 const label = querySelectorNotNull(template, '.settings-item-label');
+                /** @type {HTMLButtonElement} */
                 const button = querySelectorNotNull(template, '.action-button[data-action=import-recommended-dictionary]');
+                button.disabled = installedDictionaryNames.has(dictionary.name) || installedDictionaryDownloadUrls.has(dictionary.url);
 
                 const urlAttribute = document.createAttribute('data-import-url');
                 urlAttribute.value = dictionary.url;