The objective of this study is to assess group differences in symptom reduction between individuals receiving group cognitive behavioral therapy (G-CBT) and attention bias modification (ABM) compared to their respective control interventions, control therapy (CT), and attention control training (ACT), in a 2 × 2 factorial design. A total of 310 treatment-naive children (7-11 years of age) were assessed for eligibility and 79 children with generalized, separation or social anxiety disorder were randomized and received G-CBT (n = 42) or CT (n = 37). Within each psychotherapy group, participants were again randomized to ABM (n = 38) or ACT (n = 41) in a 2 × 2 factorial design resulting in four groups: G-CBT + ABM (n = 21), G-CBT + ACT (n = 21), CT + ABM (n = 17), and CT + ACT (n = 20). Primary outcomes were responder designation as defined by Clinical Global Impression-Improvement (CGI-I) scale (≤2) and change on the Pediatric Anxiety Rating Scale (PARS). There were significant improvements of symptoms in all groups. No differences in response rates or mean differences in PARS scores were found among groups: G-CBT + ABM group (23.8% response; 3.9 points, 95% confidence interval [CI] -0.3 to 8.1), G-CBT + ACT (42.9% response; 5.6 points, 95% CI 2.2-9.0), CT + ABM (47.1% response; 4.8 points 95% CI 1.08-8.57), and CT + ACT (30% response; 0.8 points, 95% CI -3.0 to 4.7). No evidence or synergic or antagonistic effects were found, but the combination of G-CBT and ABM was found to increase dropout rate. We found no effect of G-CBT or ABM beyond the effects of comparison groups. Results reveal no benefit from combining G-CBT and ABM for anxiety disorders in children and suggest potential deleterious effects of the combination on treatment acceptability.