The population aged ≥90 years is increasing worldwide, yet nearly 50% of elderly breast cancer (BC) patients receive suboptimal treatments, resulting in high rates of BC-related mortality. We analyzed clinical and survival outcomes of nonagenarian BC patients to identify effective treatment strategies. This single-institution retrospective cohort study analyzed patients aged ≥90 years diagnosed with stage I-III BC between 2007 and 2018. Patients were categorized into three treatment groups: traditional surgery (TS), performed according to local guidelines; current-standard surgery (CS), defined as breast surgery without axillary surgery (in concordance with 2016 Choosing Wisely guidelines)and/or cavity shaving; and non-surgical treatment (NS). Clinicopathological features were recorded and recurrence rates and survival outcomes were analyzed. We collected data from 113 nonagenarians with a median age of 93 years (range 90-99). Among these patients, 43/113 (38.1%) underwent TS, 34/113 (30.1%) underwent CS, and 36/113 (31.9%) underwent NS. The overall recurrence rate among surgical patients was 10.4%, while the disease progression rate in the NS group was 22.2%. Overall survival was significantly longer in surgical patients compared with NS patients (p=0.04). BC-related mortality was significantly higher in the NS group than in the TS and CS groups (25.0% vs. 0% vs. 7.1%, respectively; p=0.01). There were no significant differences in overall survival and disease-free survival between the TS and CS groups (p=0.6 and p=0.8, respectively), although the TS group experienced a significantly higher overall postoperative complication rate (p<0.001). Individualized treatment planning is essential for nonagenarian BC patients. Surgery, whenever feasible, remains the treatment of choice, with CS emerging as the best option for the majority of patients.