Perovskite solar cells based on organolead halide perovskite light absorbers have been considered a promising photovoltaic technology due to their superb power-conversion efficiency along with cheap material cost. Since the first work on long-term durable solid-state perovskite solar cells, a tremendous volume of research on perovskite solar cells has been carried out. A high photovoltaic performance is mainly attributed to the high-quality CH3NH3PbI3 (MAPbI3) material that is strongly dependent on the fabrication method used. MAPbI3 can be prepared by either a single-step procedure or a sequential two-step deposition technique. The two-step method was found, in general, to show better coverage, morphology, and infiltration into a mesoporous oxide layer, which led to high-quality perovskites with desirable optoelectronic properties and thereby high-efficiency perovskite solar cells.