The current concepts of cancer therapy are moving towards personalized treatment regimen aiming to reduce toxicity and improve efficacy of therapeutic agents. With the development of molecular imaging and targeted therapies personalized care has received a shot in the arm. However, these developments are not without challenges. Drug delivery, metabolism, toxicity etc. challenge the effective utilization of such agents. Nanoparticles offer to overcome these hurdles with their unique physico-chemical properties which can be labeled with radionuclides and conjugated with ligands to achieve high specific activity in the intended areas. In this article, we discuss the present status of radiolabeled nanoparticles, the areas where they are being used and challenges that lie ahead. We intend to provide a basic outlook on the utilization of radiolabeled nanoparticles in cancer diagnosis and therapy.