The prognostic factors of young breast cancer patients (BCPs) are still controversial. This study is aimed at evaluating the prognosis of young BCPs by characteristics and treatment response. We analysed the data on 2,593 operable BCPs age <or=50 years who were treated in the Cancer Hospital of Fudan University, Shanghai, China between 1990 and 2004. The overall survival and recurrence/metastasis-free survival were compared. In the study, 782 patients (30.2%) were <or=40 years, and 1,811 (69.8%) were 41-50 years old at their primary diagnosis. BCPs <or=40 years presented more unfavourable features than the 41-50 years BCPs (P < 0.05). They were more likely to experience death (P < 0.001) and recurrence/metastasis events (P < 0.001) even when they underwent the same adjuvant therapy in parallel with their counterparts (P < 0.05). In a multivariate analysis, age was an independent predictive factor for RFS (HR = 0.26, 95% CI = 0.44-0.89, P = 0.009) but not for OS (P > 0.05). Higher TNM stage and chemotherapy, but not HER2/neu over-expression, were predictive factors for young Chinese BCPs. The characteristics of breast cancer are more aggressive in young Chinese BCPs. Their prognostic factors are obviously different from those of the elder group. Current therapy was not as effective for them.