Organizational citizenship behavior towards the environment (OCBTE) represents an influential tool for environmental policy implementation in local governments. The present study examines this behavior among the immediate managers of local governments as they are considered essential conduits for transmitting environmental values to employees and citizens living in the administered municipal areas. The study's primary purpose is to explore the relationships of instrumental support for the environment (ISE) of mayors and immediate managers’ OCBTE in municipal governments through mediation-moderation analyses and bring original insights to local government governance. A cross-sectional study was carried out on a sample of 420 managers. The hypotheses were verified through structural equation modelling using SmartPLS 3.3 software. Findings indicate a direct relationship between the mayors’ ISE and the immediate management employees’ OCBTE in the municipalities. The mediating effects of the stakeholder demand (SD) and person-organization fit (POF) hypotheses were confirmed. A significant positive moderating effect of trust in the mayor was also approved. There was no moderating effect confirmed for commitment towards the mayor. These results extend our understanding of the mechanisms behind the pro-environmental micro-level additional role of employee behavior in local government settings and provide new insights into the factors that positively correlate with these behaviors.