Given the water shortage in different parts of the country, determining and evaluating the amount of virtual water and water productivity in important agricultural crops seems necessary and essential. In this study, the three indicators of virtual water (VW), physical productivity (WP), and economic productivity (NBPD) of watermelon crop in the crop year 1401 were calculated and examined in Hamedan province. The yield of the crop, the cost and income, the amount of water consumed and the irrigation requirement of watermelon were collected and calculated in the farms of the province. The results of the study showed that the highest value of the index (VW) of watermelon is 410 liters/kg in Tuyserkan county and the lowest value is 137 liters/kg in Hamedan county. Considering the area under cultivation of this crop in the counties of the province, the average value of this index for the entire province was estimated to be 184 liters/kg. Also, the highest value of the index (WP) of watermelon is 7.32 kg/m3, which is related to Hamedan county and the lowest value is 2.44 kg/m3, which is related to Tuyserkan county. Considering the area under cultivation of this crop in the counties of the province, the average value of this index for the entire province was estimated to be 5.76 kg/m3. The computational index (NBPD) in Hamedan county was the highest value equal to 364.95 thousand rials/m3 and in Bahar county the lowest value equal to -25.88 thousand rials/m3. This index was also calculated considering the area under cultivation of watermelon in the counties of the province, on average for the entire province and its value was equal to 236.17 thousand rials/m3.