Biomedical informatics aids to analyse the health conditions of patients and the efficiency of healthcare processes to help clinicians, researchers, and scientists to improve human health. It focuses on identifying trends in the data discovered through computational tools and techniques. The expansion of big data in biomedical and health field has driven the need of new effective analysis technology. In this context, Machine learning (ML) is the fastest growing field in Health Informatics (HI) having the greatest application. In this chapter we have discussed the application, challenges, and future benefits of ML to improve medical diagnoses, disease analyses, and pharmaceutical development.