This review considers the current data on the use of nanoparticles of biogenic metals and their oxides in antineoplastic treatment, the role that the metals play in important regulatory and metabolic processes, their immunotropic effects, and the possible effects on the electromagnetic parameters of cell–cell interactions. Analysis of the available data and original in vivo experimental results indicates that the antitumor potential of these agents is underestimated. Avenues of further research that may contribute to the development of new effective anticancer nanotechnologies are discussed.