An analysis for predicting the torsional capacity of reinforced concrete beams has been developed based on consideration of deformations and equilibrium at failure. Three main factors are identified as contributing to the torque capacity of a section, the total capacity being the sum of the contributions due to stirrups, dowel forces, and shear strength of concrete in the compression zone. The capacity equation so obtained has been checked with the measured failure torque of 94 beams reported in the literature. These beams include variations in stirrup and longitudinal steels, stirrup dimensions, disposition of longitudinal steel, concrete strength, etc. The close agreement between the predicted and test values proves the validity of the analysis.