: This study aimed to investigate the effects of salvianolic acid A (Sal A) on the time course of plasma and tissue dimethylarginine levels after myocardial infarction (MI) induced by left coronary artery ligation. The rats were assigned to 4 groups: Sham, MI, and MI treated with Sal A (1 or 5 mg/kg). The results showed that plasma symmetric dimethylarginine and asymmetric dimethylarginine (ADMA) levels separately reached the peak at the first and second day after MI. Dimethylarginine dimethylaminohydrolase (DDAH) activity in the heart was remarkably inhibited on the initial 2 days. Sal A restored DDAH activity in the heart and decreased the elevated plasma ADMA levels. ADMA concentrations in the heart and liver were significantly increased after MI, which could also be reduced by Sal A. In addition, Sal A showed regulating effects on symmetric dimethylarginine levels in the liver and also in the ischemic zone of heart. In conclusion, the variations of dimethylarginines in plasma and tissues were induced by the inhibition of DDAH activity and their leakage in the infarct zone after MI. Sal A exerted beneficial effects in MI by decreasing plasma and tissue dimethylarginine levels via restoring DDAH activity.