Data mining isa field of intersection of computer science and statistics used to discover patterns in the information bank. The main aim of the data mining process is to extract the useful information from the dossier of data and mold it into an understandable structure for future use. In 2000, India(31.7 million) topped the world with highest number of people with diabetes and it is also predicted that by 2030 type II diabetes may afflict to 79.4 million individuals in India. About 17.5 million people die each year in India form Heart disease. Many researchers are using different data mining tools to help medical professionals in the diagnosis of lifestyle diseases. Researchers reviewed literature on the prediction and diagnosis of heart disease and Type II diabetes by using data mining techniques and applied on healthcare data of patients. This paper highlights the important role played by data mining tools in analysis of huge volume of healthcare related data in prediction and diagnosis of lifestyle diseases. kEYWORD: Data mining Techniques; Data mining algorithms; Data mining applications.