In this work, the addition of different types (Au, Ag and Al) of metal nanoparticles (NPs) in the PEDOT:PSS hole transport layer of inverted perovskite solar cells was systematically studied. The Ag and Au NP incorporation led to the highest power conversion efficiency improvement, while the Al NP-based devices showed significantly improved stability compared to the pristine one. Efficiencies exceeding 13.5% were demonstrated.