For many years, it has been assumed that microglandular hyperplasia (MGH) of the cervix occurs almost exclusively in women with endogenous (pregnancy) or exogenous (oral contraceptives) progestational stimulation, but this relationship has never been subjected to rigorous epidemiologic study. All available cases of MGH in our 1990 surgical pathology files were reviewed and clinical histories obtained. For each case of MGH, a control was chosen, consisting of a case in the same time frame of a woman of similar age who had undergone the same procedure (biopsy, conization, hysterectomy) for the same indication. A documented history of current oral contraception or pregnancy within the past 6 months was obtained in 57.9% (22 of 38) of the MGH cases and 47.4% (18 of 38) of the controls. This difference was not statistically significant by McNemar's test for paired data. The histologic features of the MGH lesions (lesion size, cytologic atypia, prominence of inflammation, and presence of solid component and of squamous metaplasia) were evaluated blindly without knowledge of the hormonal history. There were no statistically significant differences by the chi 2 test of association between cases with and without hormonal histories. This study provides no support for considering MGH or any of its constituent features. This study provides no support for considering MGH or any of its constituent features as causally related to oral contraception or other known hormonal perturbations.