Combined small cell lung carcinoma is an uncommon entity and constitutes 1-3% of all cases with small cell lung carcinoma (SCLC). We reported three cases of combined small cell lung carcinoma. All the cases were male (ages: 77, 60 and 55 years, respectively) with a history of heavy smoking and presented with lung masses. Additionally, first case had been a history of asbestos exposure for 5-6 years. Histopathological examination of biopsy specimens revealed a rare variant of small cell lung carcinoma ie combined small cell lung carcinoma. In addition to histological evidence of small cell lung carcinoma, the first biopsy specimen also contained areas of squamous cell carcinoma and the other two biopsy specimens revealed adenocarcinomatous cells. Immunohistochemical findings supported the diagnosis. Combined small cell lung carcinoma is very rare, but is nevertheless a well described diagnostic category among lung cancers. In this case report, because of the rarity of these tumors, we discussed combined small cell lung carcinoma in view of the literature.