Health promotion campaigns are typically designed to elicit fear, yet the use of fear is often ineffective in achieving the desired behavior change. Campaigns which attempt to use fear as part of a punishment procedure are unlikely to succeed. Consistent with established principles of learning, fear is most likely to be effective if the campaign allows for the desired behavior to be reinforced by a reduction in the level of fear. This entails five requirements: 1) fear onset should occur before the desired behavior is offered; 2) the event upon which the fear is based should appear to be likely; 3) a specific desired behavior should be offered as part of the campaign; 4) the level of fear elicited should only be such that the desired behavior offered is sufficient to substantially reduce the fear; 5) fear offset should occur as a reinforcer for the desired behavior, confirming its effectiveness. Under some circumstances it may be difficult to ensure that these requirements are met. In general, a positive reinforcement approach may prove to be more effective than the use of fear.