Increasing global temperature is alarming the need for construction industry to have thermally efficient building materials. Incorporating Phase Change Materials (PCM) in buildings is widely accepted method for reduction in temperature, thereby achieving better thermal efficiency. This paper focuses on the assessment of thermal performance of PCM-incorporated building under tropical climatic condition. The simulation process was carried out using Design Builder Software and the developed building model is validated with the results available in the literature. A parametric study is also performed in order to identify the effect of different parameters like building orientation, window to wall ratio, ceiling height and construction material on the indoor air temperature. The results showed that the maximum reduction was up to 2.76°C. Keywords- Thermal Efficiency, Tropical climate, PCM