A natural history study disclosed different relationships between several types of emotions and blood lipids in a group of 24 men. Findings were cross-validated in a study of a second group of 20 men. Anxiety scores had a significant positive correlation with plasma FFA in both groups, whereas three types of hostility indexes had essentially zero correlation. More anxious men tended to have higher FFA levels and sharper rises in FFA than nonanxious men in reaction to venipuncture and free-associating for 5 min. There was evidence for positive correlations between triglyceride levels and both anxiety and hostility inward scores as well as for total hostility outward scores and levels of blood cholesterol. In contrast to other studies where higher levels of emotional arousal have often been involved and no differential relationship has been found between blood lipid levels and the kind of emotions, in this study plasma lipid levels were found differently related to anxiety and hostility at relatively low levels of acute arousal.