A Geographic Information System is a computer based system for handling spatially referenced data and information. Its versatility has made it to find applications in a number of disciplines. This paper examines its role as a tool for Environmental Planning and Management. The capabilities of GIS in handling environmental information is looked at from four perspectives: (i) environmental information data collection and management (input, update and retrieval); (ii) display and visualization of digital environmental information; (iii) spatial analysis of environmental information; and (iv) modeling scenarios. It is considered that environmental information systems that incorporate GIS provide a platform for generating information that enables insights into environmental scenarios hence allowing for proper decision making. As environmental planning and management strives to solve the needs of human beings sustainably with minimum interruption of the environment, it is concluded that GIS will continue to provide the tools for effectively carrying out these activities.