Background Same-day discharge after mastectomy is a recently described treatment approach. Limited data exist investigating whether same-day discharge can be successfully implemented in patients undergoing mastectomy with immediate implant-based breast reconstruction (IBR). Methods Patients having mastectomy with IBR from 2013 to 2019 were reviewed. Enhanced recovery with same-day discharge was implemented in 2017. Patient characteristics, oncologic treatments, surgical techniques, and 90-day postoperative complications and reoperations were analyzed comparing enhanced recovery patients with historical controls. Results A total of 363 patients underwent nipple-sparing (214, 59%) or skin-sparing (149, 41%) mastectomy with 1-stage (270, 74%) or tissue expander (93, 26%) IBR. Enhanced recovery was used for 151 patients, with 79 of these patients (52%) discharged same-day. Overall, enhanced recovery patients experienced a significantly lower rate of 90-day complications (21% vs 41%, P < 0.001), including hematoma (3% vs 11%, P = 0.002), mastectomy flap necrosis (7% vs 15%, P = 0.02), seroma (1% vs 9%, P < 0.001), and wound breakdown (3% vs 9%, P = 0.05). Postoperative complication rates did not significantly differ among enhanced recovery patients discharged same day. Postoperative admissions significantly decreased after enhanced recovery implementation (100% to 48%, P < 0.001), and admitted enhanced recovery patients experienced a lower length of stay (1.2 vs 1.8, P < 0.001). Enhanced recovery patients experienced a lower incidence of ≥1 unplanned reoperation (22% vs 33%, P = 0.01); overall average unplanned and total reoperations did not significantly differ between groups. Conclusions In conjunction with enhanced recovery practices, same-day discharge after mastectomy with IBR is a safe and feasible treatment approach.