E-commerce development led to the explosion of online payment. Consumers have many choices when deciding on the online payment method for each transaction. Using a combination of both qualitative and quantitative methods with the help of SPSS AMOS version 22.0, the article explores the factors that influence consumers’ online payment method decision behavior in Vietnam. Research results show that awareness of usefulness, awareness of risk, awareness of trust, awareness ease of use, product uncertainly perception and perceived behavioral control have effects on the behavior of deciding on online payment methods. Awareness of risk has the strongest negative impact on online payment method decision behavior and awareness of usefulness has the strongest positive impact on online payment method decision behavior. Based on these important results, the article proposes a number of implications: (i) continuing to invest and upgrade modern technology to ensure customer information absolutely confidential; (ii) converting all ATM cards on the market to EMV chip standard card technology; (iii) improving service activities, quickly handle things to create confidence for customers; (iv) credit institutions operating in the field of online payment linked to e-commerce sites, supermarkets, convenience stores, restaurants must ask partners to increase transparency for the products.