OBJECTIVE To scrutinize all colonic biopsies and document the prevalence and pattern of various colonic diseases amongst the patients presenting at a tertiary care hospital of Western Saudi Arabia. METHODS We examined the record of all colonic biopsies, processed at Histopathology Department of King Abdul Aziz University Hospital; Jeddah from January 2002 to July 2007. RESULTS The colonic biopsies received during the study period were 711. Biopsies showing inflammatory, nonspecific/infective and other miscellaneous colonic lesions were 477. Out of these, 181 patients showed nonspecific colitis, 122 showed ulcerative colitis and 15 cases were of Crohn's disease. Of the 107 benign polyps seen, the most dominant was adenomatous polyp. Out of 99 malignant cases, 94 showed adenocarcinoma. CONCLUSIONS Among Inflammatory bowel diseases, ulcerative colitis is an important disease in our society. Tubular adenomas are the most common type of polyps and adenocarcinoma is the most common malignancy of the colon.