Beef rib cuts were oven roasted at 107° and 163°C. to end points of 60°, 70°, and 77°C. Cooking losses, tenderness, and other sensory properties were evaluated and related to histological changes in muscle components. Cooking times were longer and cooking losses usually lower at 107°C. than at 163°C. As end point temperature increased, cooking time and cooking loss increased and juiciness decreased. Shear values for cuts heated to end points of 70° and 77°C. at 107°C. were lower than for all other heat treatments. Roasts cooked at 107°C. to each end point and those cooked at 163°C. to 60°C. received higher tenderness scores than did all other heat treatments. Muscle fiber diameter decreased approximately the same extent with heating at either oven temperature. Fiber diameter decreased as end point temperature increased from 60° to 70°C., but diameter increased between 70° and 77°C. Quantity of collagenous connective tissue appeared to be greater in cuts heated at 163°C. to 60°, 70°, and 77°C. and at 107°C. to 70°C. than at other heat treatments. With increasing oven and end point temperatures, collagenous tissue changed from a banded to a granular appearance and fat became dispersed in the perimysial and endomysial collagenous tissue.