Recently, artificial intelligence (AI) platforms such as ChatGPT and Google Gemini have progressed at a rapid pace. To allow for optimal medical outcomes and patient safety, it is crucial that patients have clearly written post-operative instructions. Patients are increasingly turning to AI platforms for medical information. Our objective was to evaluate the ability of ChatGPT versus Gemini to develop accurate and understandable post-operative instructions for patients undergoing endoscopic sinus surgery (ESS). Postoperative instructions on ESS, balloon sinuplasty, Caldwell Luc surgery, and septoplasty were generated using ChatGPT and Gemini. Measures of readability were calculated. The Patient Education Materials Assessment Tool was utilized to determine Understandability and Actionability. ChatGPT and Gemini were capable of generating understandable post-operative instructions but were poor for actionability and readability. While AI has a promising ability to generate accessible medical information, patients should be aware of its drawbacks especially when seeking postoperative instructions.