A well-structured smart parking system is an important component of smart cities that enables effective traffic management. Integrating several enabling technologies like Internet of Things (IoT), Unmanned Aerial Vehicle (UAV) and 5G communications can facilitate monitoring and management of parking spaces more accurately. In this paper, we propose a smart parking system that uses multiple sensors to monitor the occupancy of parking spaces, assisted by observations from UAVs to increase accuracy. The system includes interconnected wireless sensor nodes placed across each parking slot and an UAV connected to a central node. Multiple sensors assisted by UAV increase the accuracy of the system and lowers false negatives and false positives.