We report on the effect of metallic nanoparticles on the liquid-state dewetting behaviour of bismuth films. The nanoparticles and the films were grown by thermal evaporation and subjected to annealing under ambient conditions. Dewetting was analysed by morphological studies of TEM images and by calculating the surface exposure of the films. Our results show that the addition of Ag and Au destabilizes the film, while Cu has the opposite effect. This is explained by the formation of solid solutions for Bi–Au and Bi–Ag, which lower the melting point. Cu nanoparticles stabilize the film by pinning the dewetting front. This mechanism is different from solid-state dewetting where stabilization is due to the reduction in pinhole formation at the grain and triple boundaries. This study provides insight into the role of nanoparticles on the stability of metallic films and can be extended to other low melting metallic systems. © 2020 Institute of Materials, Minerals and Mining Published by Taylor & Francis on behalf of the Institute.