The relationship between the use of fertility drugs and the risk of ovarian cancer was analysed using data from an Italian case-control study. The study comprised 971 women below the age of 75 years with histologically confirmed invasive epithelial ovarian cancer diagnosed within the year before the interview. The controls were 2758 women admitted to the same network of hospitals where the cases of ovarian cancer had been identified. Five cases (0.5%) and 11 controls (0.4%) reported use of fertility drugs. In comparison with women who had never used fertility drugs, the multivariate odds ratio (OR) for women who had taken fertility drugs was 1.1 [95% confidence interval (CI) 0.4-3.3]. The OR were 0.7 (95% CI 0.1-7.9) and 1.0 (95% CI 0.2-3.8) for women who had used fertility drugs for <6 and > or =6 cycles respectively. Considering the 14 cases and 45 controls reporting difficulty in conception, the risk of ovarian cancer was 0.5 (95% CI 0.1-3.6) for women who reported use of fertility drugs. Considering nulliparous women only, the estimated OR of ovarian cancer for any fertility drug use was 0.6 (95% CI 0.1-3.5). Although the present results have limitations in terms of statistical power and available information, they provide reassuring evidence of the absence of a strong association between fertility drugs and subsequent risk of developing epithelial ovarian cancer.