Disease has become a common feature for human existence since the beginning of time. Over time, our knowledge of Science and Medicine has been expanded for a better understanding of the biological basis of any disease. Since, the last few decades, an extensive research has been going on the molecular pathogenesis of diseases. By developing a deep understanding of molecular pathogenesis, we will uncover the involvement of specific genes, proteins, and corresponding pathways to get better equipped for the development of targeted therapies for specific diseases. Continued development of our knowledge for deciphering underlying mechanisms of the disease has resulted in the development of a new era of Theranostics. Theranostics provides a targeted, safe, specific, and cost-effective treatment protocol. The proteomics, pharmacogenetics, and biomarker analysis make the backbone of theranostics. The role of theranostics is highly appreciated in the area of oncology where the nano-formulations like metallic nanoparticles, quantum dots, and carbon nanotubes, dendrimers liposomes play a pivotal role. Therefore, theranostics is a holistic transition from trial and error medicine to preventive, predictive, and personalised medicine for better treatment of diseases.