Objective. Our study’s goal was to find out acute myocardial infarction (AMI) patients’ NUMB gene expression patterns and to evaluate its role as a diagnostic marker for AMI detection. Methods. Peripheral blood was drawn from 124 individuals who had an AMI and 115 patients who had stable coronary artery disease (SCAD). The real-time quantitative polymerase chain reaction was used to measure the mRNA expression level of the NUMB gene in peripheral blood. Results. The AMI group’s NUMB gene expression was 0.906 (0.181–0.954), whereas the SCAD group’s expression was 1.024 (0.207–1.127). However, the AMI group had 0.885 times lower NUMB mRNA expression than the SCAD group P