Introduction: The main aim of the present study is to investigate the selective attention in methadone maintenance patients comparing with two control groups including the abstinent opiate abusers and healthy control subjects. Method: 25 former opiate addicts receiving methadone maintenance treatment, 25 former opiate addicts withdrawn from all opiates and 25 healthy controls without a history of drug dependence participated in this study. All groups matched by age, level of education and sex. Instruments included Dot Probe Task, Beck Depression Inventory and State-Trait Anxiety Inventory. Results: There were significant differences on anxiety and depression across three groups, which mean that the experimental group obtained high scores than the control groups. The experimental group showed an attention bias towards addiction related stimuli in dot probe task. Conclusion: Findings of this study are in line with those of the previous researches which found some neuropsychological impairment in long-term MMP recipients.