Because of extreme climate differences between the southeastern Cotton Belt region of the United States and south Texas, farmers are reluctant to adopt conservation tillage systems developed in the southeast United States. With a greater knowledge of the benefits and risks of conservation tillage practices under a subtropical, semi-arid environment, producers can make better decision regarding tillage practices. The objectives of this study were to 1) compare the effects of conventional moldboard tillage and conservation tillage on cotton yields and production costs; and 2) provide farmers with guidelines for implementing conservation tillage. Cotton lint yield and production economics as affected by tillage in a semi-arid subtropical environment was examined. Six producer fields were split and one-half of each was farmed using conventional tillage practices and one-half of each field was farmed using conservation tillage practices. Seeding rate, fertilizer, irrigation, insect management, and other production factors were the same for both tillage systems. Cotton average lint yields in the conservation tillage fields were 137 pounds greater than in the conventional tillage fields. Four of the sites had higher yields of up to 39% more lint in the conservation tillage fields, one site was equal and one site had a 3% lower yield with the conservation tillage. Production costs averaged $55/acre less in the conservation tillage fields and net returns averaged $129/acre more with conservation tillage compared with the conventional tillage methods. Results of this one year study apply to cotton following grain sorghum. Conservation tillage cotton can be produced with lower input costs and have equal or greater economic returns than the conventional moldboard plow tillage system.