Although epidemiologic studies have shown the impact of height on occurrence and/or prognosis of cardiovascular diseases, the underlying mechanism is unclear. In addition, the relation in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) remains unknown. We sought to assess the influence of height on outcomes of patients with acute STEMI undergoing primary PCI and to provide a pathophysiological explanation. All 1,490 patients with STEMI undergoing primary PCI were analyzed. Major adverse cardiac and cerebrovascular events (MACCE) were defined as all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned hospitalization for heart failure (HF). Patients were divided into (1) MACCE (+) versus MACCE (-) and (2) first- to third-tertile groups according to height. MACCE (+) group was shorter than MACCE (-) group (164 ± 8 vs 166 ± 8 cm, p = 0.012). Prognostic impact of short stature was significant in older (≥70 years) male patients even after adjusting for co-morbidities (hazard ratio 0.951, 95% confidence interval 0.912 to 0.991, p = 0.017). The first-tertile group showed the worst MACCE-free survival (p = 0.035), and most cases of MACCE were HF (n, 17 [3%] vs 6 [1%] vs 2 [0%], p = 0.004). On post-PCI echocardiography, left atrial volume and early diastolic mitral velocity to early diastolic mitral annulus velocity ratio showed an inverse relation with height (p <0.001 for all) despite similar left ventricular ejection fraction. In conclusion, short stature is associated with occurrence of HF after primary PCI for STEMI, and its influence is prominent in aged male patients presumably for its correlation with diastolic dysfunction.