Photovoltaic (PV) systems have been used globally for a long time to supply electricity for water pumping system for irrigation. System cost drops down with time since PV technology, efficiency, and design methodology have been improved and cost of wattage drops dramatically in the last decade. In the present paper optimum PV system design for water pumping system has been proposed for Oman. Intuitive and numerical methods were used to design the system. HOMER software as a numerical method was used to design the system to come up with optimum design for Oman. Also, REPS.OM software has been used to find the optimum design based on hourly meteorological data. The daily solar energy in Sohar was found to be 6.182 kWh/m2·day. However, it is found that the system annual yield factor is 2024.66 kWh/kWp. Furthermore, the capacity factor was found to be 23.05%, which is promising. The cost of energy and system capital cost has been compared with that of diesel generator and systems in literature. The comparison shows that the cost of energy is 0.180, 0.309, and 0.790 USD/kWh for PV-REPS.OM, PV-HOMER, and diesel systems, respectively, which sound that PV water pumping systems are promising in Oman.