Background: The addition of MRI to mammography for screening BRCA mutation carriers detects significantly earlier stage BC but, with median follow-up of < 10 years in all reports to date, the long-term prognosis of these cancers is uncertain. Moreover, while the short-term risk of ipsilateral recurrence for carriers who opt for breast conservation (BCT) are reported to be similar to that of non-carriers, the risk of late new breast primaries may be substantially higher. We report the long-term ipsilateral, contralateral, and distant recurrence as well as survival results for the previously unaffected women with BC diagnosed in the Toronto MRI screening study. Methods: From 07/1997 to 06/2009, 380 BRCA mutation carriers with no history of BC or ovarian cancer completed 1 to 9 rounds of annual screening with MRI and mammography; 41 cancers (30 invasive) were detected (38 by MRI, 5 by mammography) in 40 women (20 BRCA1, 20 BRCA2), median age at diagnosis 48 (32 to 68), followed annually for recurrence and survival by mailed questionnaire. 10-year results were calculated using the Kaplan-Meier method. Results: As of 01/2018, median follow up was 13.5 (8 to 19) years with none lost to follow-up. Of the 27/40 (68%) who initially had BCT, 6 (22%) had an ipsilateral recurrence/new primary at 3, 3, 6, 15, 16 and 19 years, with 2 of the latter 3 opting for repeat lumpectomy and re-irradiation. Of the 34 who did not have bilateral mastectomy initially, only 1 developed a metachronous contralateral cancer at 1 year. Of the 40 women, 34 (85%) are alive with no evidence of disease, and 6 have died: 2 (5%) of peritoneal cancer, 1 of ovarian cancer, 1 of suicide, and only 2 (5%) of ER+ BC, with distant recurrences 6 and 7 years after diagnosis. 10-year BC-specific survival was 94.6% for all 40 patients and 92.6% for those with invasive disease. Conclusions: MRI-detected BC in BRCA mutation carriers has a 10-year BC-specific distant recurrence-free survival rate of 95%. Distant recurrences occur relatively early, likely due to the known faster growth rate of these cancers. MRI-based breast screening has proven to be a very reasonable alternative to risk-reducing mastectomy.