The Extension Service is a vital division of every land grant university in the United States. Each state has a land grant university system. Mississippi State is part of the land grant university system in Mississippi. In Michigan, it's Michigan State, in Georgia it's the University of Georgia and in Pennsylvania, it's Penn State University.

As part of the land grant university system with Alcorn State University, Mississippi State has the responsibility to extend the research accomplished at the university to those in the state that can't come to the school. To do this, the Extension Service, formerly known as the Cooperative Extension Service, occupies a major division of the university. The Extension Service Director has a network of county offices throughout Mississippi that house county Extension faculty and staff who serve local clientele with information on many topics including agriculture, family and consumer sciences, economic and community resource development, and 4-H/youth development.

Extension Forestry faculty are part of the MSU Department of Forestry and serve the Extension Service through the Director and county faculty by conducting forestry educational programs, writing publications, and other educational activities.