Introduction: Attentional bias components are important factors in the etiology and maintenance of Generalized Anxiety Disorder (GAD). The purpose of this study was to examine the effectiveness of cognitive-behavior therapy in attentional bias components of patients with generalized anxiety disorder .Method: This research was administrated in a single subject experimental design framework using multiple baselines. According to the tendency of the participants, structured diagnostic interview and inclusion criteria, 2 GAD patients were selected randomly. Participants received cognitive behavioral therapy according to the Dugas’s model for GAD in twelve sessions. Patients receiving cognitive-behavior therapy were examined by the dot probe task. To analyze the data, indexes of process changes, slope and interpretation of ups & downs in charts were employed.Results: Cognitive-behavior therapy dramatically reduced delayed disengagement from threat in subjects. This means the scores during the intervention sessions were significantly reduced compared with baseline scores. The visual inspection of charts and size effects indicated significant decreases in delayed disengagement from threat in participants. No effectiveness of cognitive - behavioral therapy was seen in the facilitated attention to threat.Conclusion: Findings generally showed that cognitive-behavior therapy via directly and indirectly targeting the mechanisms of attentional bias components can be considered as an appreciate choice for the treatment of generalized anxiety disorder. These findings have constructive clinical implications in the treatment of anxiety disorder, particularly about GAD.