Previous research has shown that individuals with generalized anxiety disorder (GAD) report elevated anger compared with nonanxious individuals; however, the pathways linking GAD and anger are currently unknown. We hypothesized that negative beliefs about uncertainty, negative beliefs about worry and perfectionism dimensions mediate the relationship between GAD symptoms and anger variables. We employed multiple mediation with bootstrapping on cross-sectional data from a student sample (N = 233) to test four models assessing potential mediators of the association of GAD symptoms to inward anger expression, outward anger expression, trait anger and hostility, respectively. The belief that uncertainty has negative personal and behavioural implications uniquely mediated the association of GAD symptoms to inward anger expression (confidence interval [CI] = .0034, .1845, PM = .5444), and the belief that uncertainty is unfair and spoils everything uniquely mediated the association of GAD symptoms to outward anger expression (CI = .0052, .1936, PM = .4861) and hostility (CI = .0269, .2427, PM = .3487). Neither negative beliefs about worry nor perfectionism dimensions uniquely mediated the relation of GAD symptoms to anger constructs. We conclude that intolerance of uncertainty may help to explain the positive connection between GAD symptoms and anger, and these findings give impetus to future longitudinal investigations of the role of anger in GAD.