Hybrid organic/inorganic perovskite materials have become promising candidates for photovoltaic applications. Typically, lab-scale perovskite devices are fabricated by spin coating under inert atmosphere conditions (inert gases and low relative humidity) which is incompatible with scaling-up processing. In this paper, we report the fabrication of perovskite solar cells in ambient conditions (average 65% relative humidity) and low temperature, by using a slot-die technique in a Mini Roll coater. A detailed optimization of the deposition parameters for the constituent layers in a flexible and planar perovskite solar cell is discussed. In particular, the resulting layers morphology strongly depended upon the processing temperature. The optimized device architecture reached a power conversion efficiency up to 2.9% with good reproducibility and reporting forward and reverse performance. The obtained results suggest that the slot-die processing of flexible hybrid perovskite solar cells at ambient conditions can be achieved with significantly reduced production costs and reliable and scalable technology. (C) 2017 Elsevier Ltd. All rights reserved.