Hostility is considered to be a risk factor for coronary artery disease. Despite the findings of reduced serotonergic function and effectiveness of treatment with serotonergic agents in similar symptom complexes, there have been no attempts at using serotonergic psychopharmacologic agents to treat this population. We conducted an 8-week open trial of 10 type A, irritable men with coronary artery disease and no diagnosable psychiatric (axis I) condition to examine the effects of buspirone on these subjects. Buspirone appears to significantly reduce type A behavior, hostility, anxiety, impatience, and perceived stress.