This paper examines the effects of the state enterprise zone program in Colorado. Colorado began its enterrprise zone program in 1986, and the program is Colorado's largest single state economic development program, granting $188.6 million in tax credits through fiscal year 1994-1995. Results indicate that the Colorado enterprise zone program has had a positive and significant impact both on employment growth in zone areas and on the level of per capita income in zone areas. Other effects show mixed results.