The authors evaluated retrospectively 287 node negative breast cancer patients treated solely with surgery and followed-up for at least five years. Cases were retrospectively classified according to nuclear grade. The prognostic value of T category and nuclear grade were compared at univariate and multivariate analysis. Five-year overall or relapse-free survival was dependent on T (T1 = 0.96 or 0.86, T2 = 0.88 or 0.76, T3 - 4 = 0.58 or 0.38, T2 - 4 = 0.86 or 0.72) and on nuclear grade (G1 = 0.94 or 0.82, G2 = 0.88 or 0.74, G3 = 0.80 or 0.72, G2 - 3 = 0.88 or 0.74). Nuclear grade was associated to T category, as low grading tumors were more frequent among T1 as compared to T2 - 4 cases (chi-square = .09, df = 2, p less than 0.05), but both nuclear grade (G2 - 3 vs. G1: relative risk = 1.89, p = 0.022) and T category (T2 - 4 vs. T1: relative risk = 2.23, p = 0.013) were independently and significantly associated to overall survival. Although their limited discriminating power does not justify their clinical use in selecting high risk node negative patients to adjuvant therapy, they should be used as prognostic factors as they are as efficient as other new indicators and by far cheaper and simpler to assess.