Subterranean clover (Trifolium subterraneum L.) has been shown to be adapted to the southeastern USA. Grazing studies combining subterranean clover and bermudagrass [Cynodon dactylon (L.) Pers.] have been limited, however. Our objective was to determine steer performance and pasture production of subterranean clover-bermudagrass forage systems grazed at three forage availabilities. Nine 3.3-acre paddocks were established with ‘Tifton 44’ bermudagrass on a Houston clay (very-fine, montmorillonitic, thermic Typic Chromuderts) and over-seeded with ‘Mt. Barker’ subterranean clover. Paddocks were continuously grazed to either 1.2, 2.4, or 4.8 in. using a put-and-take method of grazing. This represented low, medium, and high forage availability, respectively. Stocking rate adjustments were made weekly, if needed. Grazing days per acre increased with decreasing forage height. Average daily gain (ADG) decreased with decreasing forage height. Gain per acre for low, medium, and high forage availability in 1988 was 243,312, and 312 lb/acre, respectively and 301,366, and 440 lb/acre in 1989. Forage samples were taken biweekly and hand separated into the following botanical components: bermudagrass, clover, dead material, and weeds. Crude protein (CP), in vitro digestible dry matter (IVDMD) or neutral detergent fiber (NDF) concentrations were not different among forage-availability treatments for any of the components of the botanical samples. Steer ADG and gain per acre were greater during the spring when subterranean clover grew vigorously than during the summer when bermudagrass was the largest component of botanical composition. The CP concentration of bermudagrass during the summer averaged 5.9 and 7.0% in 1988 and 1989, respectively, which is below the level thought to limit intake and gain by steers. Considering steer ADG and gain per acre, the optimum grazing height of a subterranean clover-bermudagrass forage system is between 1.2 and 2.4 in. Since this study lasted 2 yr, no inference could be made on the effect of grazing pressure on the long-term persistence of subterranean clover or bermudagrass.