Objective: To analyze the clinical, pathological, and sociodemographic aspects between triple-negative breast cancer (TNBC) and non-TNBC in a Brazilian cohort and identify potential prognostic factors. Methods: This hospital-based retrospective cohort study included 447 women with breast cancer treated at referral centers in Southeastern Brazil. Overall and disease-free survival were compared; prognostic factors were evaluated. Results: Triple-negative breast cancer corresponded to 19.5% of breast cancer diagnosis and was more prevalent among nonwhite and less educated women. The patients with TNBC tended to present with stage III cancer, high p53 expression, lymphocytic infiltration, and multifocality and treated with radical surgery and chemotherapy. The 5-year overall and disease-free survival were 62.1% and 57.5% for TNBC and 80.8% and 75.3% for non-TNBC, respectively ( P