Objective: To describe a set of tumor characteristics, prognosis and course of pregnancy in patients diagnosed with pregnancy-associated breast cancer (PABC). Methods. Retrospective cohort study of PABC young women. The histological profile, survival and pregnancy outcomes were assessed. Nonparametric tests, Fisher s exact test, Kaplan-Meier method, Cox regression and multivariate logistic regression were used for statistical analyses. Results. We assessed 16 PABC patients. All women self-palpated a breast mass, the women ≤ 35 years of age were diagnosed with unfavorable characteristics: advanced stage (88.8%), positive clinically lymph nodes (100%), high grade (55.5%), ER-negative (77.8%) and high-risk Nottingham prognostic index (66.7%). Seven deaths were observed with a median follow-up for overall survival (OS) of 64.5 months (range: 15-90). The 5-year OS rates were worse for patients with pathological lymph nodes > 4 (25%; p = 0.001) and with ER-negative disease (50%; p = 0.646). In our multivariate analysis, the nodal involvement was the only predictor associated to a worse OS (hazard radtio = 1.4, 90% confidence interval [CI]: 1.14 to 1.8). The following risk factors could influence in the risk of a preterm birth: mother s older age, gestational age at diagnosis and the chemotherapy during pregnancy, but their adjusted ORs of .61 (90% CI: 0.34 to 1), .80 (90% CI: 0.66 to 0.9) and .01 (90% CI: 0.00 to 0.9), respectively did not support statistically such an effect. Most cases of cases (77.7%) exposed to chemotherapy during pregnancy got a live term birth. Conclusion. Our findings described a more aggressive histological profile for youngest pregnant women coupled the delayed diagnosis might explain the high-risk of death. Simultaneous management of breast cancer and pregnancy was feasible.