This study was conducted to examine how independent audit firms in Vietnam understand and use risk based audit approach (RBAA) in audit practice. To answer the research questions, the researchers used primary and secondary data collected from 2018 to 2019. The results from the interview survey showed that audit firms were aware of the advantages of adopting RBAA. However, RBAA is practiced to a moderate extent by audit firms in Vietnam. Big 4 audit firms use RBAA more popularly than Non-Big 4 audit firms. The causes of the difference are the disadvantages of adopting RBAA and client’s characteristics such as relevant guideline, audit fees, auditors’ knowledge and experience. Besides, the study investigated factors impacting on the RBAA adoption by distributing a questionnaire to 246 auditors of 126 audit firms in Vietnam. A set of statistical appropriate methods where used through SPSS software version 22.0. The results indicated that there were six factors influencing RBAA adoption including: Auditor’s ability, Technological development, Audit fees, auditors’ motivation, Audit time and client’s risk. Of which, auditor’s ability and technological development are factors that have the most significant and positive impacts on the adoption of RBAA. Additional implications were argued in the final section of this study.