Myocardial ischemia/reperfusion (MI/R) injury usually occurs in patients with cardiovascular disease. However, myocardial reperfusion insult often induces apoptosis. It is assumed that that microRNAs (miRNAs) are involved in the pathological and physiological processes associated with myocardial ischemia/reperfusion (MI/R). In the present study, we found decreased expression of miR-342-5p in hypoxia/reoxygenation (H/R) cardiomyocyte model (H9C2 cells) and MI/R mouse model. Alternatively, overexpression of miR-342-5p was found to ameliorate myocardial cell damage in bothin vivoandin vitro. In addition, G protein-coupled receptor, family C, group 5, member A (GPRC5A) was identified as a direct target of miR-342-5p. The up-regulation of GPRC5A functioned to inhibit the previously observed protective effect of miR-342-5p in the H9C2 H/R model. Our results revealed that miR-342-5p may be a potential target for MI/R injury prevention and therapy of MI/R injury.