The objective of this study was to investigate subclinical left ventricular dysfunction in patients diagnosed with myocardial infarction with non-occlusive coronary arteries (MINOCA). Thirty-five patients with MINOCA (average age 54.26 ± 12.24 years) and thirty-five patients with ischemia with non-obstructed coronary artery disease (INOCA) (average age 55.20 ± 8.36 years) were enrolled in the study. All clinical conditions that could affect left ventricular functions were considered exclusion criteria. Echocardiographic studies were conducted in the patient and control groups in the left lateral decubitus position using a medical ultrasound device (EPIQ 7, Philips Medical System, USA). The left ventricle was examined longitudinally with apical images of chamber 4-3-2 using the available software (QLAB 6.0). There were no differences in age, blood pressure level, baseline echocardiogram measurements, and tissue Doppler parameters between the two groups. In two-dimensional speckle tracking echocardiography (2D-STE) measurements, left ventricular longitudinal strain and strain rate in systole, early and late diastole from apical 4-3-2 chamber and global measurements of each parameter were significantly decreased in the MINOCA group compared to the INOCA group (p < 0.05). A significant negative correlation was observed between the global longitudinal strain rate and the troponin I in the MINOCA patients group (r=-0.43 p = 0.009). Our study showed that while standard echocardiographic parameters for patients diagnosed with MINOCA were normal, their left ventricular systolic and diastolic functions were reduced by the 2D-STE method.