Abstract The aim of the present study was to analyze the effect of subtype and body mass index (BMI) on neo-adjuvant chemotherapy (NAC) and postoperative prognosis. Two-hundred and forty nine patients who underwent surgery after NAC were included. A multivariate analysis and survival analysis were used to clarify the relationship between BMI, subtype, and NAC. In the logistic regression model, the pCR rate had a significant relationship with the subtype and tumor stage. In the non-pCR group, more overweight patients had significantly a worse disease-free survival (DFS) compared to normal range patients (Log lank test, p < 0.05). In the Cox proportional hazards model, subtype and tumor stage were significantly associated with decreased DFS. In conclusion, patients with the ER (+), HER (−) type and a high BMI had a high risk for recurrence when they achieved non-pCR after NAC.