The purpose of this study is to investigate the impact of the differences between International Accounting Standards (IAS) / International Financial Reporting Standards (IFRS) and Vietnamese accounting regulations in the way businesses in Vietnam practice accounting. By analysing key controversial/complex standards including goodwill, foreign currency transactions, leases, intangible assets (other than goodwill), investment properties, property, plant, and equipment, and fair value in the annual reports of 29 listed companies in Vietnam, this study sheds light on the reporting behaviour of businesses in Vietnam. In particular, through the lens of institutional theory, I find that businesses in Vietnam prefer to follow the Vietnamese accounting system, even in the situation when the system does not provide adequate instructions for complex accounting standards and when permission is given to use IAS/IFRS as an alternative. I find that normative isomorphism influenced by firm characteristics such as firm size; industry; boards of directors (BOD); ownership; and Big Four auditors do not noticeably affect the accounting choices made by listed companies in Vietnam. These findings suggest that in a setting with a totalitarian history, it is not easy to introduce new accounting systems such as the IAS/IFRS.