Introduction: Stuttering is a developmental speech disorder with multiple etiological factors. Cognitive behavior therapy (CBT) has shown effectiveness in reducing anxiety symptoms and dysfluent speech in adults who stutter (AWS). So we planned to study the comparative efficacy of CBT and CBT combined with mindfulness training (MT) in AWS. Aim: The aim of this preliminary study was to examine and compare the efficacy of CBT and CBT combined with MT in reducing anxiety symptoms, and dysfluent speech and increasing communication attitude, quality of life, self-esteem and speech fluency in AWS. Method and Materials: A matched two group pretest and posttest interventional design was employed. The sample consisted of ten adults with the diagnosis of stuttering (ICD-10, 1992) who were randomly allotted to Group One (CBT; N=5) and Group Two (CBT+MT; N=5). The therapeutic program included 15-20 sessions of one hour each. Statistical Analysis: Obtained data were analyzed using the Wilcoxon Sign Rank Test for within the group, before and after intervention comparison and Mann Whitney U Test for between group comparisons. Results: Significant difference in both CBT group and CBT+MT group is observed in the area of communication attitude (U=1.00, p<0.05). Conclusion: The findings of the study show that CBT and CBT+MT are effective in the treatment of AWS, but CBT+MT is more effective than CBT alone.