Nanomedicine is a recent promising setting for the advancement of current medical therapies, in particular for cancer. Nanoparticle-mediated therapies are aimed to tackle extremely complex phenomena, involving different biochemical, mechanical and biophysical factors. Computational models can contribute to medical research by helping the understanding of biological mechanisms and by providing quantitative analyses. In this work, we report on computational models that address four main issues related to the use of nanoparticles in anti-cancer therapies, namely the delivery of nanoparticles, their uptake by cells, the release of drugs from nano-platforms and nanoparticle-based therapeutics. In silico approaches constitute a valuable tool to aid clinical studies, to guide the rational design of new nanoparticle formulations and to identify the optimal strategies for existing treatments.