In this study, the performance of a stepped solar still connected to photovoltaic thermal (PVT) water collector was numerically and experimentally analyzed. By considering energy balance for the different components of solar still system, a transient thermal model was achieved (i.e. PVT water collector, saline water, glass cover, absorber plate). Moreover, an expression for the system energy efficiency was obtained. An experimental setup was designed and manufactured. The simulation results were validated with experimental data. Then, parametric studies were performed and the influence of various design and operating parameters on the freshwater productivity, energy efficiency and output electrical power were studied. It was shown that there would be a desired value for the area of PVT water collector and mass flow rate of saline water maximizing the energy efficiency. The mass flow rate and PVT water collector area desired value was 0.068 kg/min and 1.33 m(2), respectively. Moreover, connecting the PVT water collector to stepped solar still enhanced the energy efficiency and freshwater productivity and for other uses could provide additional electrical power.