The pecking response of pigeons was reinforced when a minimum period of time had elapsed since the last response (DRL schedule of food-reinforcement). Punishment, satiation, extinction, and stimulus change were employed separately to reduce responding. When the effects of the four procedures were compared, punishment was found capable of producing a more immediate, complete and long lasting response reduction than the others. Punishment had its maximum effect on the responses that were least relevant to reinforcement. The punishment reduced the frequency of the short inter-response times to a greater extent than did either extinction or satiation. In this way, punishment actually increased the efficiency of the DRL responding.