There is no agreement in literature on the biological behavior of psammoma carcinomas of the ovary. The majority of authors consider psammoma bodies to be the result of tumour regression, associating the occurrence of psammoma bodies with longer survival. On the other hand, several studies reveal a poor prognosis for psammoma carcinomas, similar to that of other epithelial malignant tumours. In our study, the psammoma body content in 174 serous carcinomas stage III/IV was morphometrically quantified by image analysis and the results correlated to survival time and progression time. In 20 carcinomas the psammoma body content was extremely high. In such cases, DNA flow cytometry revealed these tumours to be slowly-growing. The DNA index was 1.0 (DNA-diploid) and the number of S phases was low (max. 5.9%). The five year estimate survival was 50%, as opposed to 10% for other tumours. If no methods are available for cell kinetic analysis and for objectification and quantification of psammoma body content in serous carcinomas it is sufficient to make a semiquantitative assessment of the psammoma body content to differentiate tumours with longer survival from carcinomas of poor prognosis.