Limited data exist on the effect of nonalcoholic fatty liver disease (FLD) in the setting of acute coronary syndromes. Aim: The aim of this study was to evaluate the impact of FLD on myocardial perfusion and six months of follow-up for major adverse cardiac events (MACE) in the setting of ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Subjects and Methods: We studied 122 patients (mean age 57 + 11 years and 88% were men) who underwent primary PCI for STEMI by abdominal ultrasound within 72 hours of admission. FLD was graded according to a semi-quantitative severity score as mild (score <3) or moderate to severe (score >3). Myocardial perfusion was determined by measuring myocardial blush grade (MBG) and ST-segment resolution (STR) analysis. Patients were divided into 2 groups according to FLD score (<3 or >3). Results: Patients with FLD score >3 were more likely to have multivessel disease (39% vs22% p = 0.032), absent myocardial perfusion (MBG 0/1, 58% vs 19%, p <0.0001), lower prevalence of post-procedural Thrombolysis In Myocardial Infarction (TIMI) 3 flow grade in the group with FLD >3 (62% vs 80%, p = 0.033), but no difference in the in-hospital MACE rate (17% vs 12%, p = 0.39). Conclusions: we concluded that the presence of FLD score >3 in STEMI patients treated with primary PCI correlated significantly with poor perfusion outcomes as assessed by both reduced MBG and TIMI flow score and lower EF both in-hospital and at six-months follow-up. However, we found no statistically significant increase in MACE rates both in-hospital and at follow up after six months.