Adrenomedullin (AM) gene expression was analysed in 60 cases of epithelial ovarian cancer, (29 serous, 14 mucinous, 13 endometrioid, three clear cell, and one undifferentiated) using reverse transcription-polymerase chain reaction (RT-PCR); 10 of the cases were of low malignant potential; 25 were stage I; three were stage II; 27 were stage III; and five were stage IV. The level of AM gene expression was described in terms of the relative yield of the AM gene to the beta2-microglobulin gene. AM gene expression ranged from 0.04 to 1.57 (median 0.36). The association between histological grade and AM gene expression was significant (P: = 0.027), however, the association with other clinico-pathological features, i.e. patients' age at diagnosis, stage of disease, residual tumour mass after initial surgery, and histological subtype were not significant. Survival data were available for all patients and univariate Cox regression analysis showed that the AM gene expression was significantly associated with a poor prognosis (P: = 0.019). Immunohistochemical studies showed that AM was localized in the outer cell membrane or the cytoplasm of the carcinoma cells and in the endothelial cells of the tumour stroma. The AM gene expression level may play a key role in the biology of epithelial ovarian cancer and may define a more aggressive tumour phenotype.