DNA ploidy and thymidine-labeling index (TLI) have been introduced as prognostic indicators to characterize the biological behavior of breast cancer for the selection of patients eligible for adjuvant therapy. The aim of this study was to evaluate the prognostic significance and correlation between ploidy status, TLI and other common histopathologic parameters such as histotype, stage, grading, lymph node metastasis, hormone receptors and recurrence. DNA ploidy and TLI were assessed for 68 breast cancer patients, 27 to 85 years of age. DNA histograms, analyzed with static cytometry, were: diploid in 21(31%) and non diploid in 47 (70%). High TLI values were observed in 16 cases (24%), medium values in 46 cases (68%) and low values in 6 cases (8.5%). DNA ploidy and TLI showed a statistically significant correlation, as independent parameters, with recurrence (respectively, p = 0.0267 and p < 0.0001). Therefore, DNA ploidy and TLI may be considered additional prognostic parameters to be utilized besides all the other clinical-pathologic data for the assessment of these lesions, and to plan therapeutic strategies.