Arterial compliance is found to be reduced in haemodialysis patients. It is not clear whether decreased arterial compliance in uraemic patients is a consequence of long-standing increased mean arterial blood pressure or a consequence of the uraemic state. An adequate blood pressure can be achieved by long-treatment-time dialysis of 8 h three times a week. We studied femoral and carotid artery wall properties in 24 normotensive patients on long-treatment-time dialysis and 24 normal controls matched for mean arterial pressure, age, sex, and body mass index. Arterial distensibility coefficient and compliance coefficient were determined with a vessel wall movement detector system, 24 h after dialysis in the supine position. The patients were 5.9 +/- 6.6 years on long-treatment-time dialysis at a Kt/V of 1.8 +/- 0.4. We found no significant differences in mean arterial pressure or pulse pressure between patients (85 +/- 13, 55 +/- 17 mmHg) and controls (84 +/- 6, 50 +/- 13 mmHg). Femoral distensibility coefficient and compliance coefficient were lower in patients (6.0 +/- 2.4 10(-3)/kPa; P < 0.05, 0.52 +/- 0.28 mm2/kPa; n.s.) compared to the controls (8.8 +/- 4.0 10(-3)/kPa, 0.67 +/- 0.38 mm2/kPa). No differences in carotid distensibility coefficient and compliance coefficient were found between patients (12.8 +/- 4.6 10(-3)/kPa, 0.72 +/- 0.30 mm2/kPa) and controls (14.1 +/- 4.4 10(-3)/kPa, 0.70 +/- 0.23 mm2/kPa). We conclude that patients on long-treatment-time-dialysis have an increased stiffening of the muscular femoral artery but not of the more elastic carotid artery. Results suggest that the uraemic state itself has a deleterious effect on the elastic properties of the muscular femoral artery.