Fibroids (leiomyomata) are the commonest tumours in women, but their aetiology is unknown. Epidermal growth factor (EGF) and transforming growth factor-beta (TGF beta) may be important factors involved in fibroid growth. We examined the mRNA expression of these two growth factors in fibroids and corresponding myometrium from 20 women who underwent hysterectomy because of fibroids. We also examined these factors in samples of fibroids from 9 women who underwent myomectomy after pretreatment with luteinizing hormone-releasing hormone agonists. We found that both factors were expressed in the three types of tissue examined. We also found that there was no difference in the relative abundance of either of the two growth factors between the tissues studied. Despite the lack of difference, we postulate that EGF and TGF beta may be important in fibroid growth because of a possible interaction between the two factors in this tissue.