Abstract Both gender and hostility are important contributors to coronary heart disease (CHD). However, we know little about either the interactive effects of the two variables or the mechanisms by which they may impact the development of CHD. The present study tested hypotheses concerning the relationship of gender, hostility and their interaction to blood pressure and heart rate. High and low hostile male and female subjects were selected on the basis of the Cook–Medley Hostility Scale. Blood pressure and heart rate were then recorded during a series of three experimental tasks: a physical stressor; a combined physical/emotional stressor and a cognitive task. It was found that men had consistently higher blood pressures than women, while women had higher heart rates on two of the three stress tasks. High and low hostile subjects differed in heart rate and systolic blood pressure (SBP) under the cognitive and combined physical/emotional stress conditions. And hostility and gender interacted to affect heart rate. Results were discussed in terms of possible implications for the earlier development of cardiovascular disorders in men than in women and the role of hostility in these disorders.