This study investigated the voluntary control of penile tumescence in the absence of external erotic stimulation. Twelve experimental subjects were given analogue visual feedback and monetary rewards for increase in penile diameter as measured by a strain gauge. Twelve control subjects were given no analogue feedback and noncontingent rewards but the same instructions to maximize erections. While both groups were capable of voluntary penile tumescence, significantly improved performance was observed in the experimental group. Two distinct psychophysiological patterns of voluntary penile tumescence were observed. A “tension” pattern was associated with marked heart rate acceleration, irregular respiration, and variable penile response. A “relaxation” pattern was associated with stable heart rate, regular respiration, and smooth tumescence curves. In using these procedures for the treatment of sexual dysfunctions, it is suggested that feedback and reward be given for a combined pattern of sexual and autonomic responses.