Dengue is a global health issue and is also regarded as one of the major public health concerns in the Philippines. Presented in this paper is the application of a geographic information system (GIS) in mapping dengue cases in Baguio City. A descriptive research design was utilized and mapped dengue cases were reconciled with environmental correlates such as land cover, housing information (independent, mixed, or interconnected), hydrology (water bodies and canals), urbanization level (urban or rural), elevation, soil, and land surface temperature. Moreover, demographic factors and practices were utilized for further analysis. Results show that interconnected housing, urbanization, land surface temperature, hydrology, and population density are predictors of dengue cases in Baguio City with the predictive power of 0.3810 (strong), 0.3426 (strong), 0.2509 (medium), 0.1675 (medium), and 0.1323 (medium), respectively. In the context of dengue, several data gaps in health information systems exist. Although the Manual of Procedures for the Philippine Integrated Disease Surveillance and Response (PIDSR) published by the Department of Health (DOH) of 2014 provides a detailed guide in the management and surveillance of communicable disease, the use of GIS was noted to be unspecified. Using GIS provides the possibility of harmonizing several data sets to better inform policymakers.