A combination of quantitatively evaluated morphological parameters and of conventional prognostic indicators has been used to study 19 cases of invasive ductal breast carcinoma from patients treated only by surgery, later developing recurrences or metastases. This set of patients not treated with adjuvant therapy (radiotherapy, cytostatic or hormonal therapy), was selected from 350 consecutive breast cancers which had been treated with surgical therapy. The aim was to investigate whether the morphometrical features are correlated with disease-free survival. Of the single features, the mitotic activity index (MAI) is most strongly correlated with prognosis. Ten of the 19 patients had an MAI value above 9, and all of them recurred within 18 months. In contrast, of the 9 other patients with low mitotic rate (MAI below or equal to 9), none recurred within 24 months. Further, a correlation exists between disease-free survival, mean and standard deviation of nuclear and nucleolar area, and tubular component of the tumors. There is no correlation between nuclear form factors and recurrence. The multivariate prognostic score is also significantly correlated with recurrence, but not as strongly as in other publications. This is obviously due to the blurring influence of the lymph node status, which was not significantly correlated with the prognosis. Thus, in this small set of patients not treated with any adjuvant therapy, the results of morphometric analysis are in agreement with earlier data and emphasize the prognostic significance of quantitative microscopical analysis in breast cancer.