In order to investigate the effects of different nitrogen and phosphorus levels on yield and yield components of mungbean variety Partow a field experiment was conducted at the Research Farm of the Islamic Azad University of Shahre-rey, in Tehran, Iran in 2009. The experiment was laid out with factorial arrangement in a Randomized Complete Block Design with three replications. Five levels of nitrogen (0, 30, 60, 90 and 120 kg N ha-1) and six levels of phosphorus (0, 30, 60, 90, 120 and 150 kg P2O5 ha-1) were the treatment variables. Results showed that application of N and P fertilizers significantly increased the seed yield. The maximum seed yield (224.2 g m-2) was obtained when 90 kg N ha-1 and 120 kg P2O5 ha-1 was applied. This increase in seed yield was mainly due to more number of pods plant-1, number of seeds pod-1 and 1000 seeds weight. Thus, application of 90 kg N ha-1 and 120 kg P2O5 ha-1 seems to be optimum levels for harvesting highest yield of mungbean.