This reprint is focused on the exploitation of natural nanoparticles for cancer diagnosis and treatment. It compiles articles related to exosomes and protein nanocages, but also presents the use of some organic natural compounds in cancer treatment, which have been extensively studied as agents for cancer treatment since their biological nature guarantees a better safety, biocompatibility, and biodegradability profile in comparison to synthetic nanoparticles and drugs. These features are strongly appealing in order to face cancer, where the development of tumor-targeted specific devices and the use of natural compounds could be useful in improving patient compliance.