Personalized medicine is a promising approach that uses each patient’s distinct genetic profile to customize the diagnosis and treatment of diseases. Patient’s specific therapy with understanding the inter-individual variability using genomics biomarkers leads to improved therapeutic outcomes and diminishes the side effects. Considering the limitations of conventional diagnosis and treatment, theranostics is a single system that integrates both treatment and diagnostics and could be a potential way for personalized medicine. Nanomaterials possess unique properties. It has been widely reported for targeted drug delivery, improved imaging, and therapeutic action with negligible toxicity. Nanoformulations as theranostics demonstrated their potential use in various diseases, including cancer and metabolic disorders, and could be advantageous in prevention, identification, and treatment by incorporating specific molecular characteristics of the individual patient. The exclusive properties of nanotechnology are utilized to identify the biomarker and drug delivery. Nanotheranostics can be administered noninvasively to diagnose targeted photographs of biomarkers and therapeutics delivery as per the biomarker distribution. The clinical relevance of nanotheranostics assists in earlier detection and assessment of the patients, which potentially responds to the treatment and has greater possibilities for a therapeutic outcome. The concept of nanotheranostics is highly appealing in understanding and deciding the individual therapeutic records to achieve the utmost advantages with a fewer side effects. This chapter discusses the recent advancement of emerging nanotheranostics strategies for personalized medicine.