Intercellular adhesion molecule-1 (ICAM-1), a member of immunoglobulin supergene family with a five-domain structure, is known to play an important role in inflammatory disease. We measured levels of soluble ICAM-1 in sera of 25 patients with allergic rhinoconjunctivitis (7 male, 18 female: age range 14-47 years, mean 29.8 +/- 9.2) and 20 healthy subjects (11 male, 9 female: age range 22-48 years, mean: 33.3 +/- 7.6). All allergic patients had positive history, positive skin prick test and conjunctival provocation test, and radioallergosorbent test for specific allergens. Soluble ICAM-1 in serum samples was determinated by ELISA. The mean serum sICAM-1 levels, in healthy subjects was 193.3 +/- 68.8 ng/ml and in patients with allergic rhinoconjunctivitis was 212.6 +/- 50.9 ng/ml. There were no difference in sICAM-1 levels in both of the groups (P > 0.05). In male patients with allergic rhinoconjunctivitis, sICAM-1 levels (mean: 234.5 +/- 55.0 ng/ml) were higher compared to female patients with allergic rhinoconjunctivitis (mean: 204.1 +/- 48.1 ng/ml) and control group (P < 0.05 and P < 0.05 respectively). Soluble ICAM-1 levels were high in patients with allergic rhinoconjunctivitis who had high level of symptom score.