This study delves into the influence of green human resource management (GHRM) on the environmental achievements (green performance, GP) of Spanish wineries, examining how employee wellbeing (EW) plays a mediating role. To refine the analysis, factors like age, size, and affiliation with protected designation of origin (PDO) areas are considered. Utilizing a model informed by prior research, the study analyses data from 196 Spanish wineries, collected from September 2022 to January 2023, through partial least squares structural equation modeling (PLS-SEM). Results highlight a robust, positive correlation between GHRM initiatives and wineries' GP, with EW acting as a significant intermediary. This research stands out for several reasons: it broadens the comprehension of GHRM benefits, marks the first detailed exploration of GHRM's effect on GP specifically within Spanish wineries, and is pioneering in investigating EW's mediating influence on the GHRM-GP link.