abstract In a cross-cultural experiment, we examined how task interdependence influences the importance of organizational citizenship behaviour (OCB) in employee performance evaluations in China and the USA. A total of 150 graduate students in China and 154 in the USA (a total of 304), who serve as evaluators, participated in the experiment. Participants were exposed to a task interdependence manipulation and then rated the importance of OCB in their overall performance evaluations of employees. Results support the moderating effects of national culture (both using a country proxy and as a measure of collectivism) on the affects of task interdependence. Although among evaluators from the USA perceptions of the importance of OCB increased as task interdependence increased, the effects of task interdependence were significantly attenuated among evaluators from China. Implications of these results for research and practice are discussed.