The lack of a reliable and extended system to monitor rainfall is one of the major challenges in analyzing, hydrological prediction and water resources management in Iran. Using satellite precipitation products in some parts of the country with lack or presence of low quality precipitation data, which can be used as alternative source for basins with sparse data in developing countries such as Iran, will be very useful. Hence, the main objective of this study is to evaluate and interpolate the accuracy of monthly precipitation of TRMM 3B43 v7 satellite data in Iran with ground stations. The monthly precipitation data of TRMM with a spatial resolution 0.25 × 0.25 degree were extracted and evaluated with 41 stations in the country during the periods of 1998 to 2014. To evaluate the accuracy of rainfall estimation and interpolation of error criteria, the NSE, RMSE, BIAS, ME criteria and IDW methods in ArcGIS 10.3 software were used, respectively. Generally, the results showed that more arid and semiarid regions of Iran had overestimation while underestimation was in high precipitation regions. And based on the ME, 82.93 percent of stations had upper and under estimation with limitation of less than 10 mm in month. Also, the results of rating showed that Ardebil station with total rating of 5 and Esfahan stations with total rating of 146 had the highest and lowest error of monthly rainfall estimation. In general, the results showed that monthly rainfall data of TRMM had acceptable accuracy in most parts of the country.