BACKGROUND: Cell adhesion molecules have been implicated in the various stages of tumor progression and metastasis. ICAM-1 plays a important roles in cell-cell interactions in inflammatory and immune response of several diseases. Recently, elevated levels of sICAM-1 in circulation was reported as association with liver metastasis in gastric, colonic, gall bladder and pancreatic cancer, with reduced survival in malignant melanoma. This study was performed to measure the sICAM-1 in patients with lung cancer and to evaluate the relations between staging of lung cancer and level of sICAM-1. METHODS: Serum sICAM-1 was measured in 36 patients with lung cancer according to the pathologic types and clinical staging before therapy and in 8 controls with ICAM-1 ELISA kit. RESULTS: Serum sICAM-1 levels were elevated in patients with lung cancer except small cell type. Also progression and metastasis of lung cancer associated with elevation of sICAM-1 levels. CONCLUSION: These results suggest that higher levels of serum ICAM-1 reflect the progression and metastasis of lung cancer and it may be used as a marker with diagnostic and prognostic significance.