To date no specific serological parameters are available to assess disease activity in systemic lupus erythematosus (SLE). The objective of this study was to correlate serum levels of thrombomodulin (TM), intracellular adhesion molecule-1 sICAM-1, vascular cell adhesion molecule-1 sVCAM-1, and E-selectin with standard laboratory tests and clinical indices of disease activity in 40 patients with SLE and 20 apparently healthy persons as controls. According to British Isles Lupus Assessment Group (BILAG) disease activity index, the 40 patients were divided into two groups, the first consisted of 22 with active disease, and the second consisted of 18 patients with inactive SLE. Serum sTM, sICAM-1, sVCAM-I, and E- selectin were measured in their sera, using enzyme linked immuonosorbent assay (ELISA) technique.C-reactiv protein (CRP), Erythrocyte sedimentation rates (ESR) and serum creatinines were measured by standard laboratory tests. Total leukocytic count and hemoglobin concentration were detected by coulter counter. Levels of sTM and sVCAM were highly elevated in the group of patients with active SLE as compared to the inactive one (P<0.0005) while sICAM-1 levels were moderately elevated (P<0.005). E-selectin was poorly correlated with disease activity in SLE (P>0.05). In SLE, the BILAG disease activity index, ESR and serum creatinine correlated best with sTM, sVCAM-1 and E-selectin levels while there was a weak association between CRP levels and the adhesion molecules, and no correlation between CRP level and disease activity. In conclusion, sTM and sVCAM were the most important serological indices of disease activity in SLE and might be valuable serological parameters for monitoring therapy.