Metal nanoparticles (NPs) may have the potential to overcome problems related to conventional chemotherapy. Metal NPs reported to play a beneficial and powerful role in cancer therapy providing better targeting, gene silencing and drug delivery. Functionalised metal NPs with targeting ligands offer a better control of energy deposition in the tumours. Apart from therapeutic benefits, metal NPs are also used as a diagnostic tool for the imaging of cancer cells. Metal NP-based therapeutic systems not only provide simultaneous diagnostic and therapy but also allow controlled and targeted drug release which helps to revolutionise cancer treatment and management. This review addresses the advancement of metal NPs in tumour therapy with a focus on those being explained into clinical settings.