Always make sure that you’re using the latest version of Skype for Mac OS X so that you don’t miss out on the new features and improvements.
When you delete your chat history in Skype, it removes your entire history, which includes:
SMS text messages
Sent and received files
Once your chat history has been deleted, it cannot be restored. You won't be able to recover this information.
It’s easy to delete your chat history:
Sign in to Skype.
In the menu bar, click Skype > Preferences….
The Preferences option selected in the Skype menu.
In the window that opens, select the Privacy panel.
Click Delete All Chat history. This may take a few minutes to delete.
You can also indicate how long you'd like to save your history for. In the Save chat history area, select from: 1 Month, 3 Months, 1 Year or Never.
It’s not possible to delete a part of the conversation history only, but you can delete a conversation with a particular Skype contact. This will delete all the conversations you’ve ever had with that contact.
Deleting a conversation
It’s easy to delete a conversation:
Right-click the conversation and select Delete Conversation....
The Delete Conversation option selected from the list that appears after right-clicking a conversation.
In the pop-up window, click Delete.