In an in-vitro fertilization (IVF)/embryo transfer programme granulosa cells obtained from 59 individual preovulatory follicles were analysed using multiparameter image analysis cytometry, in an attempt to determine whether their morphometric and DNA-cytometric parameters could prove useful in assessing follicle and oocyte maturity and in predicting fertilizability and outcome of these IVF cycles. Almost all morphometric and DNA-cytometric parameters were not correlated with either the patient's age or oocyte maturity, and did not predict oocyte fertilization or occurrence of a clinical pregnancy. The only possible relevant parameter which, despite its inverse correlation to total luteinizing hormone administration, also proved to be inversely correlated to pregnancy outcome (in the seven cases in which a pregnancy occurred), was the percentage of granulosa cell nuclei with increased DNA content (> 5c). Finally, if granulosa cells do not reveal euploid polyploidization in spontaneous or induced ovulatory cycles, the detected cells with increased DNA content should be interpreted as aneuploid, i.e. with chromosomal aberrations, and so their presence could also be discussed in connection with the hypothetical risk of prospective neoplastic transformation of the tissue.