Leiomyoma of the uterus is a frequent benign tumor of non menopausal women. Among possible complications, polycythemia is rare and often unrecognised. We report a very demonstrative case, that of a 52-year-old woman, who presented initially an episode of metrorrhagia. The difficulty of diagnosis and the treatment are detailed. The different physiopathological hypotheses are discussed in order to ameliorate our knowledge about this association between fibromyoma and polycythemia, and to optimise therapeutic management.