This sub-study of the SORT OUT IX trial sought to compare clinical outcomes between patients with diabetes randomized to implantation of either the polymer-free biolimus A9-coated BioFreedom stent (BF-BES) or the ultra-thin strut, biodegradable polymer sirolimus-eluting Orsiro stent (O-SES). Patients with diabetes have an increased risk of target lesion failure (TLF) after percutaneous coronary intervention (PCI). The impact of different stent types in patients with diabetes is still discussed. A total of 607 of the 3151 patients (19.3%) enrolled in the SORT OUT IX study had diabetes. Randomization was stratified by patients with/without diabetes; 304 received BF-BES and 303 O-SES. The primary endpoint was TLF, which was a composite of cardiac death, myocardial infarction (not related to other than the index lesion) and target lesion revascularization (TLR) within 1 year. After 1 year, patients with diabetes had higher TLF (7.2% vs. 3.7%, incidence rate ratio [IRR]: 1.65; 95% confidence interval [CI]: 1.08–2.50), than patients without diabetes. TLF did not differ significantly between BF-BES and O-SES in patients with diabetes (8.2% vs. 6.3%, IRR: 1.17; 95% CI: 0.63–2.20). In patients with diabetes, cardiac death occurred in 2.3% of BF-BES and in 3.6% of O-SES (IRR: 0.58; 95% CI: 0.23–1.45) and TLR occurred in 5.3% and 2.3% of BF-BES and O-SES, respectively (IRR: 2.12; 95% CI: 0.81–5.56). Definite stent thrombosis rates of 1.3% were found in both stent types. Patients with diabetes had higher 1-year TLF rate after PCI compared to patients without diabetes, whereas TLF did not differ significantly between the two stent types BF-BES and O-SES in patients with diabetes.