The authors present the case of a young woman who had Hodgkin's disease when she was 29 years of age. This was treated with 5 courses of M.O.P.P. (Mustard (nitrogen mustard), Oncovin, Procarbazine, Prednisone). These courses were followed by radiotherapy and the patient was given the combined oestrogen-progesterone pill while under treatment. After 20 months following treatment the patient was clinically and biologically menopausal. She was treated with hormone replacement therapy on alternate months. 10 months later, she started a twin pregnancy (there was no family history of twins) and after 37 weeks of amenorrhoea she delivered twins weighing 2,180 g and 2,300 g. The review of the literature shows that the ovaries are affected by this type of treatment, which causes ovarian fibrosis and failure of maturation, with disappearance of follicles. The effects of such treatment are variable and may leave the patients with normal ovarian function, or with a menopause from the outset. The essential prognostic feature is the age of the patient at the time of treatment. The dose of the antimitotic drugs used does not seem to have a great effect on ovarian function. The role of giving oestrogens and progestogens is disputed. The fact that twins occurred in this case could be explained by the fact that twin pregnancies do occur more often in the pre-menopause because the higher levels of gonadotrophins ripen several follicles.(ABSTRACT TRUNCATED AT 250 WORDS)