PurposeThe purpose of this paper is to examine the determinants of mutual funds' performance at both a country level and a fund level in Vietnam.Design/methodology/approachThe different types of funds with more than three-year operation are selected to remove outliers of the stock market boom from 2015 to 2018. The data set includes 54 mutual funds operating during the period from 2008 until November 2018.FindingsThe research finds that there is a positive relationship between macroeconomics and mutual funds' performance. Furthermore, country-level governance such as regulation effectiveness, political stability, economic growth and financial development has a positive correlation with mutual funds' performance. However, the impact of fund-level factors is diverse with the no significant impact of board size on mutual fund's performance, while passive funds perform better than active funds in Vietnam.Practical implicationsThe research results suggest that investors should pay attention to the types of funds and operating expense when making an investment decision in mutual funds. There are some recommendations for both government policy-makers and the mutual fund industry that are likely to facilitate the development of this field in Vietnam.Originality/valueThe research contributes to the understanding of what are the factors that should be considered when investing in mutual funds.