We report here three cases of squamous-cell carcinoma of the esophagus following endoscopic injection sclerotherapy for esophageal varices. All three patients were men and cigarette smokers, with a mean age of 58.3 +/- 5.0 years. Hepatitis B and C virus infection tests were negative, and alcoholic cirrhosis was present in each patient. The interval between sclerotherapy and the development of carcinoma was 9, 10, and 33 months, in the respective cases. The sclerosant used was 5% ethanolamine oleate with a mean total volume of 51.0 +/- 18.9 ml. While we have no evidence of a direct relationship between sclerotherapy and esophageal cancer, in patients with alcoholic cirrhosis who have risk factors for esophageal cancer there may be an acceleration of the potential malignancy, as a result of the chronic inflammation related to sclerotherapy. Such patients should be closely followed, using endoscopy.