The integration of various information systems in different areas is a manifestation of technological sophistication. The main purpose of this study is to integrate Geographic Information System in monitoring disease affected-areas in Tandag City, Surigao del Sur, Philippines. This will help the government health agencies visualize significant information relevant to their decision-making towards health intervention. The disease cases involved in the study is limited to Dengue, Malaria and Measles. The development of the GIS for this purpose uses specific software called "QGIS". Upon utilization of the GIS, results reveal pattern of relationship among population and disease-affected areas relatively.