OBJECTIVE To compare the value of head-chest lead electrocardiogram (HCECG) and routine lead electrocardiogram (RLECG) in diagnosis of acute positive posterior myocardial infarction. METHODS HCECGs and RLECGs were recorded simultaneously in 68 normal individuals and 32 patients with acute posterior wall myocardial infarction confirmed by coronary angiography and echocardiography. Each HCECG and RLECG was analyzed by two senior physicians specialized in clinical electrophysiology who were blinded to the results. The HCECG- and RLECG-based diagnostic results were compared with the results of coronary angiography, and the coincidence rates and false positive rates of diagnosis based on HCECGs and RLECGs were calculated. RESULTS The coincidence rate was 93.8% (30/32) for RLECGs and 100% (32/32) for HCECGs in the diagnosis of acute posterior wall myocardial infarction, showing no significant difference between them (P>0.05). RLECGs-based diagnosis, however, resulted in a significantly higher false positive rate than HCECGs [13.2% (9/68) vs 0% (0/68), P<0.05]. CONCLUSIONS Head-chest lead system is superior to routine lead system for its low false positive rates in the diagnosis of acute posterior wall myocardial infarction.