Background: Left ventricular (LV) thrombus is a complication of acute Myocardial Infarction (MI) and is associated with systemic thromboembolism. Although standard trans-thoracic echocardiogram (TTE) is commonly used for screening, it is limited by low sensitivity for detection of LV thrombus. Magnetic resonance imaging has a high yield in detection of these thrombi. Objective: To determine rate of detection of left ventricular thrombi on magnetic resonance cardiac viability studies. Design: Retrospective, observational. Setting: Department of Radiology at a Hospital in Dhahran from April 2013 to April 2018. Patients and Methods: All recently reperfused ST Segment Elevation MI (STEMI) patients who were referred for MR cardiac viability studies with negative TTE (for LV thrombi) were evaluated. Patients with limited or incomplete studies, previously known MI or cardiac surgeries, and those contraindicated to MRI were excluded. An area of low signal intensity with no late gadolinium enhancement (LGE) was defined as thrombus on MR imaging, and two radiologists made consensus reporting for the diagnoses. Patients with anterior or non-anterior wall MI were documented, and their ejection fractions were recorded. The percentage estimation for positive LV thrombi cases was made. Any complications (like stroke or death) that occurred within one year of diagnoses were documented. A Chi-square and t-test determined the association. Main Outcome Measures: Detection of LV thrombi. Sample size: 125 patients. Results: Of the 125 patients, most were men (71.2%) with a mean age of 56.78 years. Eleven patients had left ventricular thrombi (8.8%), and most of these were anterior wall infarctions with low ejection fractions (<40%). Three out of 11 patients with LV thrombi developed complications versus 3 out of 114 without LV thrombi. Conclusion: Cardiac MR viability studies can detect LV thrombi in recently reperfused echo-negative STEMI patients. Limitations: Retrospective, small sample, single center, use of non-contrast echocardiography