Temporary organizations such as projects are known to differ in various respects from permanent ones and have been argued to be more gender-neutral. Inspired by gender research in permanent organizations, we show that (in)congruency between gender and project roles evokes similar mechanisms in both permanent and temporary systems. Using the example of cooperative behavior, operationalized as project citizenship behavior (PCB), we examine how temporary organizations reward such behaviour. A cross-sectional study was conducted, with 241 project managers and workers participating. The results of seven structural equation models reveal that though the enactment of PCB does not vary by gender, the relationship of PCB with its outcomes does: men and women were clearly rewarded differently depending on the gender congruency of their project roles. (C) 2015 Elsevier Ltd. All rights reserved.