In this paper, a study has been carried out to evaluate the performance of the 1.8 kW(p) rooftop photovoltaic system. This paper presents the result obtained from monitoring of 1.8 kW(p) crystalline photovoltaic system mounted on inclined iron structure on a flat roof of Ghaziabad, India. The system was monitored for one year and all the electricity generated was fed to the domestic load at 220 V, 50 Hz. Daily, monthly and annually performance parameters of the PV system are evaluated which include: average generated energy (kWh) per day, average system efficiency, average charge controller efficiency, average inverter efficiency, average array efficiency, average power output, solar radiation around the year, performance ratio, capacity factor, reference yield, array yield, final yield, temperature loss, array capture loss and system loss. The average electrical energy generated was 3.75 kWh/day/kW(p), the average solar radiation per day was 5.0 kWh/m(2)/day, the average PV module efficiency was 10.5%, the average PV system efficiency was 8.05%, the average inverter efficiency was 85.81%, the charge controller efficiency 95.96%, the average reference yield was 4.89 kWh/kW(p)/day, the average Array yield was 4.16 kWh/kW(p)/day, the average final yield in outdoor test condition was 3.1 kWh/kW(p)/day, the Performance ratio of the system per month was 63.27, capacity factor was 12.9 %, the average temperature was 0.26 hour/day, the average array capture loss was 0.73 hour/day, the average system loss was 1.06 hour/day. These results show it is highly imperative to develop evaluation, analysis, and application technology of crystalline Rooftop PV system in India.