A number of studies in environmental disclosure have suggested that corporates accountable for environmental responsibility practice have lower cost of capital. However, this relationship has not yet been discovered in Vietnam. The purpose of this study is to examine the relationship between environmental disclosure and the equity cost of 115 non-financial companies listed on Vietnamese stock market from 2014 to 2017 with 460 observations. This study uses the panel data regression model (the fixed effects model (FEM) and the random effects model (REM)) to assess the impact of environmental disclosure on the equity cost of listed companies in Vietnam. Content analysis method according to GRI guidelines is used to measure the level of the environmental responsibility practice and Easton’s model (2004) is used to estimate firms’ ex ante cost of equity. The research results show that the level of environmental information disclosure of listed companies in Vietnam is not high and there is a negative relationship with statistical significance between the environmental disclosure and cost of equity of listed companies in Vietnam. The findings suggest that environmental practice can be profitable and beneficial to Vietnamese listed companies. Therefore, companies in Vietnam need to change their awareness of social and environmental responsibility practices. This study also shows that the suitable model for listed companies in Vietnam is the FEM.