A model hypothesizing that task interdependence affects supervisor-reported extrarole behavior indirectly through employee felt responsibility was tested in this study. The model was supported by path analysis in a sample of 290 health-care and administrative employees in two hospitals. The results (a) demonstrate the importance of asymmetric felt responsibility to extrarole behavior and (b) show the need to include mediating psychological states when testing the effects of workplace structures on extrarole behaviors. New scales for measured employee-perceived task interdependence are introduced.