Most modern hospitals have accepted the principle of examining microscopically all tissue removed by operation. While gynecologists adhere to this rule regardless of the size of the specimen, most proctologists regard histologic study as unnecessary when small amounts of tissue are removed, especially when hemorrhoidectomy is performed. During the last six years we have studied by microscopic methods every specimen removed during anorectal operation, no matter how small the lesion and how harmless its gross appearance. Reviewing our clinical and pathologic records of 951 proctologic patients, it is evident that in the majority of cases nothing has been detected by histologic study which changed the prognosis or treatment based on clinical examination. This, however, is true also in the fields of major surgery and gynecology. There are, on the other hand, so many cases in our material in which the microscopic examination revealed conditions which were not suspected clinically that