Grid-connected rooftop photovoltaic (PV) systems are becoming very common in commercial as well as domestic settings due to a) lowering of PV system prices and b) increased emphasis on reducing CO2 emissions for electricity production. Polycrystalline-silicon (p-Si) modules are most commonly used for these PV systems due to mature technology and lower module costs. Newer thin-film module technologies such as amorphous Si (a-Si), Cadmium Telluride (CdTe) and Copper Indium Selenide (CIS) are also increasing their market share due to performance gains in high-temperature environments. This paper conducts a techno-economic analysis of p-Si and CIS systems under similar ratings and environmental settings (irradiance, temperature, rainfall, and dust). The case study simulates electricity production from two 42 kWp PV systems and compares the simulated results with one year measured data of the deployed systems at Lahore University of Management Sciences (LUMS), Lahore, Pakistan. Results show that CIS is a better choice from performance ratio perspective as its annual energy production is higher than p-Si. However, p-Si has a better levelized cost of electricity which makes this technology a more viable commercial solution in Pakistan. Furthermore, the area required to implement the p-Si system is significantly lower than the CIS based systems making it more attractive for areas with space constraints. The insights developed in this work can aid PV designers in the optimized selection of a rooftop PV system technology. (C) 2020 Elsevier Ltd. All rights reserved.