Green human resource management (GHRM), a set of human resource management practices targeted at environmental goals, has been proposed as the key to achieve sustainable organizational development. However, the mechanisms through which GHRM influences pro-environmental employee behavior are not yet understood fully. Drawing on the conservation of resources (COR) theory, this study presents an integrated model linking GHRM to employees’ voluntary workplace green behavior (VWGB) via employee environmental commitment and emotional exhaustion. Path analysis based on data from 396 employees partly supported our hypotheses. Specifically, GHRM was found to positively influence employees’ VWGB through environmental commitment, while simultaneously enhancing employee emotional exhaustion, thus decreasing their VWGB. Meanwhile, supervisory support for environmental behavior was found to mitigate the impact of GHRM on emotional exhaustion as well as the relationship between GHRM and employee VWGB via emotional exhaustion. This study contributes to the GHRM literature in particular and to organizational environmental management in general.