In recent decades, acceptance of nanoparticles (NPs) in therapeutic applications has increased because of their outstanding physicochemical features. By overcoming the drawbacks of conventional therapy, the utilization of metal NPs, metal-oxide, or metal supported nanomaterials have shown to have significant therapeutic applications in medicine. This is proved by a lot of clinical and laboratory investigations that show improved treatment outcomes, site-specific drug delivery, and fewer side effects compared to traditional medicine. The metal NPs interaction with living cells (animal and plant) showed many ways to develop therapeutic models with the NPs. Despite all of the advancements that science has achieved, there is still a need to find out their performance for long-term use to solve modern challenges. In this regard, the present documentation reviews some potential metals, including silver (Ag), gold (Au), zinc (Zn), copper (Cu), iron (Fe), and nickel (Ni) NPs, as therapeutic agents in various areas such as anticancer, antimicrobial, antidiabetic, and applicable for the treatment of many other diseases. Depending on the outstanding ongoing research and practical trials, metal-based NPs can be considered the hope of prospective modern therapeutic areas.