Cancer is the leading cause of death worldwide, which generates an immediate requirement for developing therapeutic and diagnostic tools to treat different kinds of cancer. Further, the onset of nanobiotechnology has opened the gateways for the development and research at the nanoscale levels. The unique size of nanoparticles helps them create distinguished properties that differentiate them from the bulk matter and hence awakens their more potentialities and utilities in multiple domains. However, one of the highly studied nanoparticles for the treatment of cancer is the iron nanoparticle because it shows high magnetism, as well as their unique structure, which helps them act as an efficient anticancer agent. Further, the biogenic iron nanoparticles are biocompatible and less toxic due to their bio-based synthesis routes, which use microorganisms, plants, biomolecules, etc. Hence, this featured article is dedicated to enhancing the knowledge on the potentialities of biologically synthesized iron nanoparticles in cancer therapy and diagnostics.