Triple mosaicism of 45, C—/46/47, C+ (most likely XO/XX/XXX) was found in 2 women with history of fetal wastage. One of them also presented with subfertility. Both were of normal phenotypes and had had regular menses. The first patient showed an increased total finger ridge count which is compatible with the finding of an XO cell line. The fetal wastage and subfertility may be explained by the presence of 45, X cells. It is also possible that the presence of 47, XXX cells may give rise to some degree of ovarian dysfunction. Couples with history of subfertility and/or multiple spontaneous abortion should be studied cytogenetically not only to detect balanced structural abnormality but also to search for chromosomal mosaicism.