Data mining has been used intensively and extensively by many organizations. In healthcare, data mining is becoming increasingly popular, if not increasingly essential. Data mining applications can greatly benefit all parties involved in the healthcare industry. For example, data mining can help healthcare insurers detect fraud and abuse, healthcare organizations make customer relationship management decisions, physicians identify effective treatments and best practices, and patients receive better and more affordable healthcare services. The huge amounts of data generated by healthcare transactions are too complex and voluminous to be processed and analyzed by traditional methods. Data mining provides the methodology and technology to transform these mounds of data into useful information for decision making. There are two main methods of Data mining: Clustering and Classification. In many cases the concept of classification is confused by means of clustering, but there is difference between these two methods. According to the perspective of Machine learning clustering method is unsupervised learning and tries to group sets of objects having relationship between them, whereas classification method is supervised and assigning objects to sets of predefined classes. in proposed system are classified and cluster of the thyroid disease in data mining.