We report a pedigree in which three sisters had a particular type of ovarian cancer, small cell carcinoma of the hypercalcaemic type. This rare type of ovarian carcinoma is now well characterised by clinical and pathological findings and is well distinguished from other ovarian epithelial tumours and ovarian germ cell tumours. The occurrence of this rare type of cancer in several members of the same family and the existence of four other similar published observations raises the question of the genetic determination of this kind of tumour.