The Nottingham prognostic index (NPI), based on tumour size in breast, node involvement and Scarff-Bloom-Richardson (SBR) grading, has been shown to constitute a definitive prognostic factor of primary operable breast cancer in the adjuvant setting. We performed a retrospective study to evaluate the prognostic value of this index in 163 patients after neoadjuvant chemotherapy. Secondly, we examined the influence on survival of a revised NPI, only based on residual tumour size in breast and SBR grading in 228 patients, and consequently called breast grading index (BGI). The prognostic value of these two indices was also evaluated by replacing the SBR grade with the MSBR grade, a French modified SBR grading; the modified NPI (MNPI) and modified BGI (MBGI) were, respectively, obtained in 153 and 222 patients. At a median follow-up of 9.3 years, survival was significantly related to these four indices (P<0.001). Multivariate analysis revealed that MBGI was the only one which retained a prognostic influence on disease-free survival (P<0.02). In conclusion, the 'amount' of residual tumour in breast and/or nodes, as defined by NPI and revised indices, confers a determinant prognosis after neoadjuvant chemotherapy, inviting an alternative postsurgical treatment for a subgroup of patients with a decreased survival.