Cancer therapy is a fast-emerging biomedical paradigm that elevates the diagnostic and therapeutic po-tential of a nanovector for identification,monitoring,targeting,and post-treatment response analysis.Nanovectors of superparamagnetic iron oxide nanoparticles(SPION)are of tremendous significance in cancer therapy because of their inherited high surface area,high reactivity,biocompatibility,superior contrast,and magnetic and photo-inducibility properties.In addition to a brief introduction,we summarize various progressive aspects of nanomagnets pertaining to their production with an emphasis on sustainable biomimetic approaches.Post-synthesis particulate and surface alterations in terms of pharmaco-affinity,liquid accessibility,and biocompatibility to facilitate cancer therapy are highlighted.SPION parameters including particle contrast,core-fusions,surface area,reactivity,photosensitivity,photodynamics,and photothermal properties,which facilitate diverse cancer diagnostics,are discussed.We also elaborate on the concept of magnetism to selectively focus chemotherapeutics on tumors,cell sorting,purification of bio-entities,and elimination of toxins.Finally,while addressing the toxicity of nanomaterials,the advent of ultrasmall nanomagnets as a healthier alternative with superior properties and compatible cellular in-teractions is reviewed.In summary,these discussions spotlight the versatility and integration of multi-tasking nanomagnets and ultrasmall nanomagnets for diverse cancer theragnostics.