The application of unmanned aerial vehicles (UAV) in Malaysia, or best known as a drone, is changing from time to time. Today, drones are used not only in the military, but also in agriculture. The use of drones became common in agriculture due to a reduction in cultivated land, labour shortages and obsolete methods. The spraying of pesticides and herbicides may also be carried out using drones. Furthermore, the time-consumed using drone is faster compared to the conventional method. On the market, there are different kinds and types of drone sprayers. Although the manufacturer has set the Standard Operating Procedure (SOP) for drone usage, the efficacy of spraying should first be examined because of Malaysia's weather and environmental factors which vary from other countries. The purpose of this paper is to investigate the effects of altitude and speed of the drone onto the coverage area during spraying application. In this study, a plot consisting of 0.5 Hectares situated at MARDI Seberang Perai was used. Three different speeds of 2 m/s, 3 m/s, and 4 m/s and three altitudes measured in heights of 1.5 m, 2.0 m, and 2.5 m from the top of the crop were tested. Wind speed and direction were recorded using an anemometer during the study. Water-sensitive paper was used during the experiment to examine the effect on spraying. In order to calculate the coverage area percentage, the spraying effect on water sensitive paper was analysed using ImageJ software. The results are expected to show which speed and altitude may contribute to the largest area of coverage percentage. The appropriate altitude and speed for the spraying operation on the basis of crop requirements can be concluded from the result which is 2 m from above crop at speed of 2.5 m/s.