Elevated serum triglyceride and low serum HDL cholesterol levels have been reported to be risk factors for occlusive vascular disease. In 20 middle-aged men with psoriasis the serum lipoprotein pattern was compared with that in a group of healthy middle-aged men. In thirteen of the 20 patients the psoriasis was mild to moderate and in seven patients it was severe and widespread. Both groups of patients had elevated levels of both VLDL and LDL triglycerides. They also showed a tendency towards higher VLDL and lower HDL cholesterol levels than the controls. The abnormalities were more pronounced in patients with severe psoriasis. The lipoprotein pattern found in this study may possibly indicate that psoriasis is associated with an increased risk of occlusive vascular disease.