Introduction: Single center suggested that acute myocardial infarction (AMI) in patients admitted with diabetic ketoacidosis (DKA) are associated with high morbidity and mortality and prolonged hospitalizations. However, confirmatory large-scale data are lacking.Methods: We utilized the national inpatient sample to identify adult patients who are admitted with a principle diagnosis of DKA (ICD-9-CM codes 250.10-250.13). We then assessed the incidence of AMI in those patients and compared in-hospital morbidity and mortality and resource utilization in DKA patients with and without AMI.Results: Between 2003-2014, a total of 230,786 patients were admitted with a principle diagnosis of DKA (national estimate 1138449). Of those, 2245 patients (1%) had a subsequent AMI during the hospitalization. Compared with patients who did not suffer an AMI, those with AMI were older (56 ±14 vs. 33 ± 16 year, p<0.0001) and had higher prevalence of prior coronary artery disease (34.3% vs. 3.3%, p<0.0001). Unadjusted mortality was 11-folds higher in patients with AMI compared with those without AMI (3.3% vs. 0.3%, p<0.0001). After propensity matching, morbidity and mortality, length of stay, non-home discharge rates and cost of hospitalization were all higher in the AMI group (Table-1).Conclusion: AMI complicates 1% of all admissions for DKA in the United States. AMI complicating DKA is associated with substantial increase in in-hospital morbidity and mortality and resource utilization. Further studies are needed to identify preventative and therapeutic strategies to improve the outcomes of these high-risk patients.