The main aim of the current research is to investigate the effect of urban agriculture on the efficiency of domestic water supply in the regions characterized by urban agriculture in the Gaza strip. Field survey to determine the sources of water for agricultural purposes and water meter readings were conducted for the two main cities which characterized by various sub-urban districts. Excel, 2007 program and SPSS, v. 15 were used to analyze the relation between water supply, the unaccounted for water and the agricultural areas within the districts of the city. The districts with urban agriculture in sub urban areas in Beit Lahya and Rafah city have 47 and 73% of unaccounted for water, additionally, correlations among the agricultural area and the unaccounted for water were shown R2= 0.622 and 0.44 for Beit Lahya and Rafah, respectively. Indicating that the high unaccounted for water refers to the illegal use of domestic water distribution networks for urban agriculture. It is highly recommended for the relevant institutions to adopt clear policy to regulate and enhance sustainable urban agriculture without depleting the water resources. Moreover, urban agriculture should be considered by urban planners concerning water use, food security and poverty alleviation in the Gaza Strip