Unmanned Aerial Vehicles (UAVs) require advanced path planning and obstacle avoidance algorithms for navigation. In this paper, the Flood Fill Method (FFM) was employed for navigating an autonomous quadcopter in a simulated environment created using MATLAB. The proposed method was compared with the traditionally used Potential Field Method (PFM). For a known terrain, Flood Fill Method works computationally faster for a repetitively same path. These methods were compared in terms of the parameters such as avoiding random obstacles for variable starting and destination positions, the time required to complete the journey, and the optimum path selection. © 2019 IEEE.