When a persuasive communication causes a change in belief, will behavior relevant to the belief also change? Past experiments have shown both successes and failures in obtaining such behavior change. The present study offers a reconciliation for these differences in findings by showing that the pattern of belief change with no behavior change occurred only in Ss who, before a communication, committed themselves to a position opposing it. Without this commitment, Ss showed no immunity against the effects of the communication on behavior. Some theoretical implications of this finding were discussed briefly.