Cell-bound adhesion molecules are involved in immune and inflammatory responses. Soluble forms of adhesion molecules (s.a.m.) can be detected in the blood. The elevated blood levels of s.a.m. were found as a response to variety disease processes (e.g. septic shock, acute graft rejection, atherosclerosis). The objective of the present study was to measure the serum levels of s.a.m. in patients with chronic renal allograft rejection and in recipients with a stable graft function. Evaluated was also the effect of activity of graft rejection (ch. g. r.) and risk factors of graft lesion on the levels of the investigated s.a.m. 34 patients with ch.g.r. were examined (Group I), 50 patients with a stable allograft function (Group II), and 25 healthy subjects (control). Group I patients were 76 +/- 34 months and Group II patients were 59 +/- 36 months after transplantation. Both groups of patients were treated with immunosuppressive drugs (CsA, azathioprine and prednisone) Group I patients had a higher plasma levels of creatinine and uric acid, increased arterial blood pressure and triglycerides concentrations, and lower plasma levels of HDL cholesterol, as compared to Group II patients. In all the examined subjects, serum concentrations of s.a.m. from the immunoglobulin and selectin families (s.ICAM-1, s.VCAM-1, s.E-selectin) were measured by the immunoenzymatic method. The investigations of s.a.m. in ch.g.r. patients revealed a statistically significant increase the serum levels of s.ICAM-1, s.VCAM-1 and s.E-selectin. Some disorders of the release of s.a.m. into blood were also found in patients without graft disfunction. In this patients were observed: increased levels of s.VCAM-1 and s.E-selectin. S.ICAM-1, s.VCAM-1 and s.E-selectin serum levels showed a correlation with plasma uric acid concentration and arterial pressure, whereas the other two molecules with the plasma level of triglycerides. Each of the three molecules had a negative correlation with the HDL cholesterol level. The regression analysis revealed a correlation of s.ICAM-1 and s.VCAM-1 with IL-6. The correlation of the molecules with chemokines (s.VCAM-1 and s. E-selectin with IL-8, and s. E-selectin with MCP-1) may results from their release in the course of the inflammatory process. The increased levels of circulating s.VCAM-1 and s.E-selectin found in renal allograft patients suggest a chronic stimulation and activation of the endothelium. Non-immunological mechanisms (such as arterial hypertension or metabolic disorders) contributed to the generation of the s.a.m. in patients with ch.g.r. and in those with stable graft function. The negative correlation of HDL with s.a.m. (s.ICAM-1, s.VCAM-1) suggests a protective role of HDL on the vascular endothelium by inhibiting the generation of these mediators.