Circulating intercellular adhesion molecule-1 (C. ICAM-1) level was measured in serum from 22 female patients with systemic lupus erythematosus (SLE) by enzyme immunoassay. Fifteen healthy females matched for age were chosen as a control group. The concentration of C3 and C4 complement were measured in the serum by single radial immunodiffusion technique and compared with its concentrationin in the control group. Disease activity was evaluated with systemic lupus erythematosus dis¬ease activity index (SLEDAI). Results showed significant increase in the level of C. ICAM-1 in SLE patients compared with normal controls and was greater in patients with active compared with inactive SLE. There was a significant decrease in the level of both serum C3 and C4 complement in SLE patients as compared to healthy con¬trols. Level of C. ICAM-1 correlated significantly with increased ESR and there was negative significant correlation between C. ICAM-1 and both C3 and C4 in SLE pa¬tients. So, the measurement of C. ICAM- 1 could be recommended as a parameter of activity in patients with SLE.