We aimed to investigate the safety of same-day discharge (SDD) after percutaneous coronary intervention (PCI) for non-ST segment elevation acute coronary syndrome (NSTEACS), and to investigate the reduction in duration of hospitalization achievable by SDD.Previous studies have established the safety of SDD after elective PCI, while the safety of SDD after non-elective PCI for acute coronary syndrome has only been sparsely studied.A single-center, observational, retrospective study of 923 consecutive procedures in patients with NSTEACS who had PCI was performed. The procedures were divided into 2 groups based on postprocedural management: SDD (n = 195) and non-SDD (n = 728).No differences were seen in the total number of adverse events at 1 month (1.5% SDD vs 1.4% non-SDD; P=.74), 3 months (2.5% SDD vs 2.3% non-SDD; P=.80), and 6 months (3.5% SDD vs 3.3% non-SDD; P=.84) after discharge, and there were no deaths in the SDD group. No difference was found in unplanned rehospitalizations within 6 months (20.5% SDD vs 25.3% non-SDD; P=.17), while unplanned revascularizations were more frequent in non-SDD patients (5.6% SDD vs 13.4% non-SDD; P.01). Median duration of hospitalization was 1.3 days shorter for SDD patients than for non-elderly, uncomplicated non-SDD patients.SDD after PCI in a selected group of NSTEACS patients was associated with low rates of adverse events, unplanned rehospitalizations, and revascularizations. SDD was associated with a shorter hospitalization duration.