Patients with diabetes mellitus are prone to increased adverse outcomes after percutaneous coronary intervention, even with contemporary drug-eluting stents. Randomized controlled trials have demonstrated comparable clinical outcomes between an ultrathin bioresorbable-polymer sirolimus-eluting stent (BP-SES) and a thin-strut durable-polymer everolimus-eluting stent (DP-EES) that has specific labeling for patients with diabetes. We aimed to evaluate the safety and efficacy of the BP-SES in patients with diabetes mellitus. To determine the performance of the BP-SES in diabetic patients, patient-level data from the BIOFLOW II, IV, and V randomized controlled trials were pooled. The primary end point was target lesion failure (TLF), defined as the composite of cardiovascular death, target-vessel myocardial infarction, ischemia-driven target lesion revascularization, and definite or probable stent thrombosis, at 1 year. Among 1,553 BP-SES and 791 DP-EES patients, 757 diabetic patients were identified. Of the diabetic patients included in this analysis (494 BP-SES vs 263 DP-EES), the proportion of insulin- and noninsulin-treated patients was similar between groups. The 1-year TLF rate in the diabetic population was 6.3% in the BP-SES group and 8.7% in the DP-EES group (hazard ratio 0.82, 95% confidence interval 0.047 to 1.43, p = 0.493). There were no significant differences, based on stent type or diabetes treatment regimen, in TLF hazards. In a patient-level pooled analysis of the diabetic population from randomized trials, 1-year clinical safety and efficacy outcomes were similar in patients treated with ultrathin BP-SES and thin-strut DP-EES.