We have evaluated established risk factors (tumor size, menopausal status, receptor status, tumor histology, and grading according to Bloom & Richardson including subfactor analysis) as well as local therapeutic procedures in a series of 121 patients with axillary node-negative (ANN) breast cancer stage T1a and T1b. The patients were operated on at a single institution (Department of Surgery, Hanuschkrankenhaus, Vienna) from 1969 to 1989. After a median observation time of 185 months, a total of 16 patients (13%) had a recurrence; of these, 6 had died of the primary disease by the control date (Dec 1, 1990). Grading (distant recurrence-free survival (DRFS) p = 0.01, overall survival (OS) p = 0.006, mitosis rate (DRFS p = 0.006, OS p = 0.02), and particularly nuclear pleomorphism (DRFS p = 0.0002, OS p = 0.00001) proved to have prognostic impact on distant recurrence-free survival and/or overall survival (Mantel-Cox log rank test; level of significance: p = 0.006 after adjustment for multiple testing by Bonferroni correction). Therapeutic procedures had a borderline-significant impact on local recurrence (p = 0.09). No other parameters had statistically significant impact. Thus, our long-term analysis confirms the superior prognostic relevance of histologic grading and nuclear pleomorphism in patients with ANN breast cancer stage T1a and T1b.