In terms of evaluating the water security situation of communities, it is necessary to use appropriate indicators. To do this, composite indicators are especially useful for policy-making on water resources, aiming to enhance water security, implementation, and monitoring of policy actions. The composite indicators of water security at the national level reflect the country's status in terms of water resource sustainability, human well-being, and water environment. In this study, the composite indicators of water security for D-8 countries were investigated in various dimensions using the data envelopment analysis model. Moreover, the status of selected countries was examined with regard to indicators related to the dimension of water security sustainability. The results provided by the proposed model showed that Malaysia, Bangladesh, Indonesia, Nigeria, and Turkey have better positions regarding the sustainability dimension compared to other countries. The water exploitation intensity in these countries was less than 40 %. Furthermore, the level of water availability in Malaysia, Bangladesh, and Indonesia was higher than 7000 cubic meters per person. It is worth noting that Low exploitation intensity and high availability of water in a country increased its water security in terms of sustainability dimension. The low water availability and very high water exploitation in Iran, Pakistan, and Egypt exacerbate their insecurity in the sustainability dimension. Due to the importance of the sustainability dimension in determining the water security status of countries, it is recommended to take this dimension into account.