Abstract Background: Various alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) exist in the pancreas. Moreover, ADH and ALDH are present in pancreatic cancer cells. The activity of ADH class III isoenzymes is significantly higher in cancerous than in healthy tissues. The expression of these enzymes in cancer cells is reflected by increased enzyme activity in the sera and thus could be helpful for diagnosing pancreatic cancer. The aim of this study was to investigate the potential role of ADH and ALDH as tumor markers for pancreatic carcinoma. methods: Serum samples were taken from 165 patients with pancreatic cancer and 166 healthy controls. Total ADH activity and class III and IV isoenzymes were measured by photometric and ALDH activity, ADH I and II by the fluorometric method. Results: There was a significant increase in the activity of ADH III isoenzyme (14.03 mU/l vs 11.45 mU/l; p < 0.001) and total ADH activity in the sera of pancreatic cancer patients compared to the control. The diagnostic sensitivity for ADH III was 70%, specificity 76%, positive and negative predictive values were 79% and 71% respectively. Area under ROC curve for ADH III was 0.64. Conclusion: The results suggest a potential role for ADH III as a marker of pancreatic cancer