Objectives Because the full version of the Post-Traumatic Growth Inventory was considered too long, a short English version (10 items/five factors) was initially proposed in the literature (PTGI-SF). Thereafter another short Italian version (10 items/five factors) and a unidimensional English version (11 items) were proposed. This study aimed at evaluating which of these three versions of the PTGI-SF could be best adapted to women diagnosed with breast cancer. Design Cross-sectional and psychometrics study. Methods A total of 239 breast cancer patients or survivors were included in the study. To assess all items related to the different PTGI-SF candidate versions; the full-length PTGI has been used to measure PTG. A set of psychometric analyses, including a confirmatory factor analysis, composite reliability and construct validity has been performed. Results The English unidimensional version did not fit the data (SB-Chi(2) = 184.47, df = 42, p < .001; SB-RMSEA = .119; SB-CFI = .814; SB-TLI = .757; SRMR = .083). Both the English (SB-Chi(2) = 61.40, df = 25, p < .001; SB-RMSEA = .078; SB-CFI = .948; SB-TLI = .907; SRMR = .048) and Italian (SB-Chi(2) = 26.52, df = 25, p > .05; SB-RMSEA = .016; SB-CFI = .998; SB-TLI = .996; SRMR = .026) versions (10 items/five factors, respectively) showed satisfactory psychometric results. Conclusion Further investigations are thus required to identify which of these two versions of the PTGI-SF is the most appropriate for women diagnosed with breast cancer.