The objective of this study was to determine whether fertility preservation (FP) with oocyte/embryo cryopreservation is associated with differences in disease-free survival (DFS). This retrospective study included patients aged 18 to 45 who were diagnosed with invasive breast cancer between 2007 and 2017 and were seen for FP consultation at a university fertility center before cancer treatment. The primary endpoint, DFS, was defined as the time from FP consultation until patients developed a locoregional recurrence, distant metastasis, a contralateral breast tumor, or a new primary malignancy. DFS was compared for FP versus no FP using Kaplan-Meier survival estimates and Cox proportional-hazard regression analysis. The study included 329 women, with 207 (63%) in the FP group and 122 (37%) in the no FP group. Patients who underwent FP had more aggressive initial disease profiles than those in the no FP group. In addition, they were younger (35 vs 37 years; P = .009), more often had stage II or III disease (67% vs 55%; P = .03), and had higher rates of requiring chemotherapy (77% vs 65%; P = .01). Over a median follow-up of 43 months, the rates of DFS were similar among patients in the FP group and the no FP group (93% vs 94%, respectively; hazard ratio [HR] 0.7; 95% CI, 0.3-1.7). Positive ER status (79% vs 83%; P = .38), neoadjuvant chemotherapy (41% vs 48%; P = .32), ER-positive DFS (HR, 0.4; 95% CI, 0.1-1.6), and neoadjuvant chemotherapy DFS (HR, 1.4; 95% CI, 0.2-9.1) were similar in the FP and no FP groups, respectively. At a median follow-up of 43 months, FP appears unlikely to affect DFS, even in the setting of tumors with positive ER status or treatment with neoadjuvant chemotherapy (in which the tumor remains in situ during FP). © 2019 American Cancer Society.