Prior studies suggest that public service motivation (PSM) is associated with individuals’ pro-environmental behaviors (PEBs), but these studies have been observational and thus have not manipulated PSM experimentally to estimate its causal effect on PEBs. Thus, this study draws on a pre-registered survey experiment with 376 public school teachers in the Kurdistan Region of Iraq to examine the influence that activating PSM has on public school teachers’ non-workplace pro-environmental behavioral intentions (PEB-I). Our results show that experimentally activating PSM leads to respondents forming higher PEB-I. Further, we observe that PSM activation has a larger effect on PEB-I for participants with higher overall levels of PSM. By experimentally estimating the effect of PSM on PEB-I, this study enhances our understanding of the causal effects of PSM not only in the workplace but in the wider social world.