Obtaining a residence permit in Cairo involves submitting an application to the Egyptian Passports and Immigration Administration. You'll need to provide essential documents like a valid passport, visa, and proof of residence, along with any additional documents depending on your purpose of stay (e.g., work contract or educational enrollment). It's recommended to start the process upon arrival and seek assistance from a local lawyer or immigration consultant to ensure a smooth application process. Remember, processing times may vary, and it's essential to maintain a valid permit throughout your stay.