Introduction: Colorectal cancer (CRC) is a common disease in all the developed nations of the world. Given the high incidence and high mortality rates for advanced disease, new prevention strategies are needed. A possible protective effect for estrogens on colon cancer risk has been suggested by numerous epidemiological and experimental studies. Estrogen replacement therapy is estimated to reduce colon cancer risk in postmenopausal women. Aim of the work: The aim of this study is to investigate the expression of estrogen receptors alpha (ERα) in malignant and premalignant colorectal lesions. The potential clinical significance of this study is that ERs may mediate chemopreventive effects for estrogens in the colon and selective ER ligands might be a colon cancer prevention strategy. Patients and Methods: Tissue samples from 70 cases with cancer colon and rectum, adenomatous polyps, inflammatory bowel disease and normal colonic mucosa were obtained endoscopically and examined by immunohistochemistry for ERα receptors. Results: ERα is present in 35.8% of cases of colorectal adenomatous polyps, 4.7% of cases with CRC and absent in mucosa of IBD cases. ERα was also present in 10% of normal colorectal mucosa. Conclusion: Erα is present in colorectal adenomatous polyps and it showed a positive correlation with the degree of dysplasia. The relation is not entirely clear but most probably it has a causal role as it is absent in the near-by normal colonic tissue. Further studies with large number of patients are needed to confirm these results.