Here, we address the issue of water management for potato (Solanum tuberosum L.) crops under arid conditions in Saudi Arabia over a 5-year period (2011-2016). Daily evapotranspiration for irrigated potato crops (ETc) was determined over a period of three successive seasons. Non-weighing (drainage) lysimeters were used in four regions: Riyadh, Qassiem, Eastern Province, and Al-Jouf. Crop coefficients (Kc) were determined using lysimetric data and an alfalfa-based reference crop evapotranspiration (ETr) during each growing season. Measured (M-ETr) and predicted, (P-ETr) for different regions were compared. Comparisons between M-ETr and P-ETr show higher trends for the measured values in all regions, with averages of 5.72 mm/d, 4.42 mm/d, 5.06 mm/d, and 7.94 mm/d for the Riyadh, Qassiem, Eastern Province, and Al-Jouf regions, respectively. Differences in the ETr and ETc were also observed among the regions due to geographic and climatic variations. In addition, the water-use efficiency of potato crops was generally highest (5.45 kg m-3) in Riyadh and lowest (1.54 kg m-3) in Qassiem. Analysis of projected net returns for irrigated potato production revealed that greater economic potential exists.