ABSTRACT Background: Ischemic heart disease is the leading cause of death and disability in the world with a fairly high portion coming from countries Low- and Middle-Income (LMICs). In Pakistan, 54% patients acute coronary syndrome (ACS) was resistant to clopidogrel, and no data on clopidogrel resistance on ethnic Minang. This study aims to look at the characteristics and P2Y12 Reactivity Unit (PRU) from ACS patients in Dr. M. Djamil Hospital, Padang. Methods: This research is a cross sectional study. The effectiveness of clopidogrel on platelet reactivity identified through examination of PRU value using VerifyNow® with a cutoff point is 208. From the PRU values, it can be classified whether patients resistant or responsive. The study was conducted in September 2016. Result: From 14 patients with ACS who received clopidogrel, 11 patients (78.57%) are male with 3 female patients (21.43). The mean of age was 53.78 years old. Patients mostly came from West Sumatra provinces (92,85%) and 7,15% from others. From all of patients head risk factors of coronary arterial disease. Hipertension was the greatest risk factor. Conclusion: It can be concluded that most of the patients were male. From PRU data, 7 patients (50%) were resistant and 7 patients (50%) were response to clopidogrel. Further research is needed with larger numbers of patients and investigate pharmacogenetic profile of CYP2C19 as caused of resistance.