This study compares the incidence of local and regional recurrence of breast cancer between two contiguous time windows in a homogeneous population of 137 patients who underwent fat tissue transplant after modified radical mastectomy. Median follow-up time was 7.6 years and the follow-up period was divided into two contiguous time windows, the first starting at the date of the radical mastectomy and ending at the first lipoaspirate grafting session and the second beginning at the time of the first lipoaspirate grafting session and ending at the end of the total follow-up time. Although this study did not employ an independent control group, the incidence of local recurrence of breast cancer was found to be comparable between the two periods and in line with data from similar patient populations enrolled in large multicenter clinical trials and who did not undergo postsurgical fat tissue grafting. Statistical comparison of disease-free survival curves revealed no significant differences in relapse rate between the two patient subgroups before fat grafting and after fat grafting. Although further confirmation is needed from multicenter randomized clinical trials, our results support the hypothesis that autologous lipoaspirate transplant combines striking regenerative properties with no or marginal effects on the probability of post-mastectomy locoregional recurrence of breast cancer.