Background Cardiogenic shock (CS) is a systemic disorder associated with dismal short-term prognosis. Given its time-dependent nature, mechanical circulatory support may improve survival. Intra-aortic balloon pump (IABP) had gained widespread use because of the easiness to implant and the low rate of complications; however, a randomized trial failed to demonstrate benefit on mortality in the setting of acute myocardial infarction. Acute decompensated heart failure with cardiogenic shock (ADHF-CS) represents a growing resource-intensive scenario with scant data and indications on the best management. However, a few data suggest a potential benefit of IABP in this setting. We present the design of a study aimed at addressing this research gap. Methods and design The Altshock-2 trial is a prospective, randomized, multicenter, open-label study with blinded adjudicated evaluation of outcomes. Patients with ADHF-CS will be randomized to early IABP implantation or to vasoactive treatments. The primary end point will be 60 days patients’ survival or successful bridge to heart replacement therapy. The key secondary end point will be 60-day overall survival; 60-day need for renal replacement therapy; in-hospital maximum inotropic score, maximum duration of inotropic/vasopressor therapy, and maximum sequential organ failure assessment score. Safety end points will be in-hospital occurrence of bleeding events (Bleeding Academic Research Consortium >3), vascular access complications and systemic (noncerebral) embolism. The sample size for the study is 200 patients. Implications The Altshock-2 trial will provide evidence on whether IABP should be implanted early in ADHF-CS patients to improve their clinical outcomes.