In order to assess the prevalence of leiomyomata in patients diagnosed with acromegaly, files of all women so diagnosed were obtained (n = 25). Eight of these patients had undergone hysterectomy. In eight of the remaining patients, assessment of the uterus was performed by gynaecological examination and transvaginal ultrasound. The prevalence of leiomyomata was 81% (13/16) in patients who had undergone hysterectomy (8/8) or who underwent gynaecological examination (5/8). In conclusion, the very high prevalence of leiomyomata in patients diagnosed with acromegaly warrants the inclusion of growth hormone excess as a cause of leiomyomata. Leiomyomata are a feature of the organomegalic syndrome associated with acromegaly.