Cancer is one of the most important health problems in the world and the treatment approaches are still challenging and generally not at desirable levels. Conventional anti-cancer agents may cause systemic toxicity, have poor solubility, and lack of selectivity. In order to overcome these hurdles, nanoparticle based therapeutics have been widely employed to enhance therapeutic efficacies and reduce systemic toxicity of pharmaceutical agents. In recent years, nanoparticulate carrier systems (NPCs) in medicine have attracted considerable scientific attention and interest in the worldwide because of their unique properties in the diagnosis and therapy of many diseases including cancer. One of the therapeutic strategies of NPCs is protein based nanoparticles. Human serum albumin (HSA) and bovine serum albumin (BSA) are the most frequently used materials for this purpose due to their remarkable advantages. In this review article, we focused on protein based nanoparticles and summarized their important applications including anti-cancer drug delivery, photodynamic therapy, and gene delivery.