The focus on the human development indicators has been increasing. A number of studies focusing on the institutional and economic effects of immigration, brain drain and development of human capital through increased investments has been performed. However, the present study evaluates the effects of these variables on the environmental sustainability of the ASEAN countries for the period ranging 1990-2019. The study evaluates the causal and magnitude of these indicators on the environmental sustainability. The study focuses on the evaluation of the data by means of a unit root test, panel cointegration test, estimation procedure and the causality analysis. The results show that the variables are integrated at the first order and are stationary, also the variables showed cointegration and long run relationships. The FMOLS estimation process using the grouped and pooled estimation technique has been used. The results show that the effects of immigration are insignificant on environmental sustainability, brain drain has an inverse relation and the human capital investments show positive associations with environmental sustainability. Moreover, the causality analysis also shows positive causal associations to be present between the dependent, independent and control variables. The study has important theoretical and practical implications as well.