Background: The sirolimus-eluting stent has demonstrated the least amount of late lumen loss among previously released drug-eluting stents, but its safety and efficacy has not been compared head-to-head with the everolimus-eluting stent. Method: The Scandinavian Organization for Randomized Trials with Clinical Outcome (SORT OUT) IV trial was designed as a prospective, multi-center, open-label, all-comer, two-arm, randomized, non-inferiority study comparing the everolimus-eluting stent with the sirolimus-eluting stent in the treatment of atherosclerotic coronary artery lesions. Based on a non-inferiority design, power calculations estimated a needed enrolment of 2,678 patients. The primary endpoint is a composite of cardiac death, myocardial infarction, and stent thrombosis or target vessel revascularization after 9 months. Data on clinical events and mortality for all randomized patients will be obtained from national databases at 9 months. No clinical follow-up examination is scheduled. Conclusion: The SORT OUT IV trial will directly compare clinically relevant differences in efficacy and safety in two drug-eluting stents: a first-generation sirolimus-eluting stent versus a second-generation everolimus-eluting stent. The study makes use of clinical endpoints routinely collected in computerized healthcare registries, allowing complete follow-up of a large, well-defined population without scheduled angiographic examinations.