The aim of our study was to determine the parameters intrinsic to ductal infiltrating carcinoma. 42 cases of about the same diameter (greater than 1.5 and less than 2.5 cm) with a minimum follow-up of more than seven years were selected. The nuclear and nucleolar shape parameters of one hundred cells for each case and the DNA content of 100 nuclei were measured by static cytometry. By means of multivariate discriminant analysis, the nucleolus/nucleus ratio and the DNA content proved to be the two best prognostic indicators based only on the examination of the parameters of the primary neoplasia. We were able to correctly classify 90% of the cases, and in particular to assign 100% of living cases and 81% of deceased ones to their exact categories.