diff --git a/telethon/client/chats.py b/telethon/client/chats.py
index 71c6be91..a04370ce 100644
--- a/telethon/client/chats.py
+++ b/telethon/client/chats.py
@@ -1147,20 +1147,28 @@ class ChatMethods:
 
     async def get_permissions(
             self: 'TelegramClient',
-            channel: 'hints.EntityLike',
+            entity: 'hints.EntityLike',
             user: 'hints.EntityLike'
     ) -> 'custom.ParticipantPermissions':
-        channel = await self.get_input_entity(channel)
+        entity = await self.get_input_entity(entity)
         user = await self.get_input_entity(user)
         if helpers._entity_type(user) != helpers._EntityType.USER:
             raise ValueError('You must pass a user entity')
-        if helpers._entity_type(channel) != helpers._EntityType.CHANNEL:
-            raise ValueError('You must pass a channel entity')
-        participant = await self(functions.channels.GetParticipantRequest(
-            channel,
-            user
-        ))
-        return custom.ParticipantPermissions(participant.participant)
+        if helpers._entity_type(entity) == helpers._EntityType.CHANNEL:
+            participant = await self(functions.channels.GetParticipantRequest(
+                entity,
+                user
+            ))
+            return custom.ParticipantPermissions(participant.participant, False)
+        elif helpers._entity_type(entity) == helpers._EntityType.CHAT:
+            chat = await self(functions.messages.GetFullChatRequest(
+                entity
+            ))
+            for participant in chat.participants.participants:
+                if participant.user_id == user.id:
+                    return custom.ParticipantPermissions(participant.participant, True)
+
+        raise ValueError('You must pass either a channel or a chat')
 
     async def get_stats(
             self: 'TelegramClient',
diff --git a/telethon/tl/custom/participantpermissions.py b/telethon/tl/custom/participantpermissions.py
index 25641b30..654f32b6 100644
--- a/telethon/tl/custom/participantpermissions.py
+++ b/telethon/tl/custom/participantpermissions.py
@@ -5,25 +5,93 @@ class ParticipantPermissions:
     """
     Participant permissions information
     """
-    def __init__(self, participant):
+    def __init__(self, participant, chat):
         self.participant = participant
+        self.is_chat: bool = chat
 
     @property
     def is_admin(self):
-        return self.is_creator or isinstance(self.participant, types.ChannelParticipantAdmin)
+        return self.is_creator or isinstance(self.participant, (
+            types.ChannelParticipantAdmin,
+            types.ChatParticipantAdmin
+        ))
 
     @property
     def is_creator(self):
         return isinstance(self.participant, types.ChannelParticipantCreator)
 
     @property
-    def is_default_permissions(self):
-        return isinstance(self.participant, types.ChannelParticipant)
+    def has_default_permissions(self):
+        return isinstance(self.participant, (
+            types.ChannelParticipant,
+            types.ChatParticipant,
+            types.ChannelParticipantSelf
+        ))
 
     @property
     def is_banned(self):
         return isinstance(self.participant, types.ChannelParticipantBanned)
 
     @property
-    def is_self(self):
-        return isinstance(self.participant, types.ChannelParticipantSelf)
+    def ban_users(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.ban_users
+
+    @property
+    def pin_messages(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.pin_messages
+
+    @property
+    def add_admins(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat and not self.is_creator:
+            return False
+        return self.participant.admin_rights.add_admins
+
+    @property
+    def invite_users(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.invite_users
+
+    @property
+    def delete_messages(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.delete_messages
+
+    @property
+    def edit_messages(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.edit_messages
+
+    @property
+    def post_messages(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.post_messages
+
+    @property
+    def change_info(self):
+        if not self.is_admin:
+            return False
+        if self.is_chat:
+            return True
+        return self.participant.admin_rights.change_info