this presentation highlights the role and need of MIS. it also includes the data flow within databses, datawarehouses and datamarts. It includes the functions of OLAP AND OLTP. It briefs about how data gets converted into information called as data mining. Further sections include different kinds of MIS management levels and managers . Then the outputs of MIS in the form of MIS reports have been illustrated with diagrams. in the later section, MIS and decision making has been discussed in details. concept of SWOT ANALYSIS and Cost benefit analysis has also been described . Structured, Unstructured and semi-structured decisions have also been discussed in detail.