Hybrid photovoltaic (PV)/diesel power systems can be used to upgrade power generation systems in medical clinics to improve the delivery of local health services. This study presents the design of hybrid (PV/diesel) power systems for medical facilities in the Agbani district (Nkanu-West) in Eastern Nigeria with a daily load of 19 kWh d-1. Solar resources for the design of the system were obtained from the NASA Surface Meteorology and solar energy website at a location of 6° 00’ N latitude and 7° 00’ E longitude, with annual average solar radiation of 4.95 kWh m-2 d-1. The design is based on theoretical model of the power stations using Hybrid Optimization Model for Electric Renewables (HOMER) software. The model was designed to provide an optimal system configuration based on hour-by-hour data for energy availability and demands. Energy source, energy storage and their applicability in terms of performance are discussed. From the simulation results, it is shown that the designed hybrid PV/diesel system reduces the operational cost and quantity of air pollutants from a diesel-only system. Details of the comparisons are presented.