The interactive effects of success importance and task demand upon cardiovascular reactivity were investigated in 2 experiments. In Experiment 1, Ss learned that success on an easy or difficult memory task would allow them to avoid a mild or severe noise. As expected, pretask and task elevations in heart rate and systolic blood pressure increased with difficulty only when the noise was to be severe. In Experiment 2, Ss listened to a victim, attending either to how she must feel or to technical features of the presentation. Then they were given the chance to earn a donation by succeeding on an easy or difficult memory task. Pretask cardiovascular data accorded with predictions predicated on the assumption that the need to help would be greater among victim perspective Ss. For them, systolic elevations increased with difficulty, whereas for technical perspective Ss systolic elevations were low regardless of task demand.