Unmanned Aerial Vehicles (UAVs) can be classified according to their civilian and military use and performance characteristics such as weight, distance to air, wing load, range and speed. In this study, the types of engine used in unmanned aerial vehicles and the advantages, disadvantages and differences between these types of engines are mentioned. Unmanned Aerial Vehicles(UAV) are used in many different tasks and need different engine types depending on the area they are used to perform these tasks. Two-stroke, Turbofan, Turboprop, Piston engine, Electric and Propeller types are different types of engines used in Unmanned Aerial Vehicles(UAV). Piston engines and electric engines are the most commonly used types. Unmanned Aerial Vehicles(UAV) also vary in engine size and type, as well as aircraft sizes and weights, as in humans. Electric engines are generally used in light and small models, while piston engines are used in heavy and large models.