Organometal halide perovskites as hybrid light absorbers have been investigated and used in the fabrication of perovskite solar cells (PSCs) due to their low-cost, easy processability and potential for high efficiency. Further enhancing the performance of solution processed PSCs without making the device architecture more complex is essential for commercialization. In this article, the overall improvement in the performance of ZnO nanowires (NWs)-based PSCs fabricated under ambient conditions, incorporating Ag nanoparticles (NPs) delivering a device efficiency of up to 9.7% has been demonstrated. This study attributes the origin of the improved photocurrent to the improved light absorption by localized surface plasmon resonance (LSPR) with the incorporation of Ag NPs. These findings represent a basis for the application of metal NPs in photovoltaics and could lead to facile tuning of optical absorption of the perovskite layer giving higher current-density (J_SC) and suppressed recombination effects leading to higher open-circuit voltage (V_OC).