The effects of reinforcement and social pressure on conformity were studied. 60 male and 60 female college Ss were assigned to 1 of 6 experimental conditions and were tested via a social conformity apparatus in a reinforcement session (1) and again in a posttest nonreinforcement session (2) 2 weeks later. Ss were subjected to social pressure during both sessions. Some groups were reinforced for agreeing, others for disagreeing, and different reinforcement schedules were employed. The results were as follows: (a) Conformity was a function of the degree and type of reinforcement-Ss reinforced for agreeing with a contrived consensus (social pressure) conformed significantly more than those reinforced for disagreeing, the extent of the effect being related to the amount of reinforcement; (b) Ss conformed more in Session 1 than in 2, but their conformity in Session 2 was a function of the treatment they received in Session 1; (c) some groups of Ss conformed more to perceptual items than to verbal items; (d) there were no sex differences in conformity. The situational factor of reinforcement is an important determinant of conforming behavior. Conformity was explained in terms of social learning and cognitive dissonance.