Malacoplakia is a chronic xanthogranulomatous inflammation that most commonly affects the urinary tract and the gastrointestinal system of middle-aged women. It is rarely encountered in a female genital tract, and only a handful of cases of malacoplakia of the ovary have been described. We report an unusual case of malacoplakia extensively involving the ovary, fallopian tube and uterus of a 47-year-old woman with poorly controlled diabetes mellitus. Escherichia coli was cultured from the ovarian lesion. To our knowledge, such an extensive female genital malacoplakia associated with diabetes mellitus has not been reported before. Widespread or atypical site malacoplakia occurring in a patient with systemic disease may result from a diminution of macrophagocytic function, either under the influence of the systemic illness or related to corticosteroid excess. We propose that diabetes mellitus without appropriate medical control may have resulted in impaired leukocyte function which, when combined with E. coli infection, led to the development of extensive malacoplakia in the genital tract of this patient.