The present research was aimed to study the effectiveness of Mind Simulation Model of Mohammad Ehsan Taghizadeh (MSMMET) on treatment of stuttering of individuals between 20 and 39 years old. The present study was in the framework of a single group semi-clinical trial design with 42 individuals between the age of 20 and 39 years old with stuttering and referred to mind empowerment clinic. The sampling method was convenience sampling method. The clients were of tonic and clonic stuttering who were divided into 5 levels of A, B, C, D and E (means very severe, severe, moderate, mild and very mild stutter) according to the clinical diagnosis of Dr Taghizadeh. These individuals were treated for 5 to 15 sessions in proportion to the level of stuttering. The extent of stuttering were classified to 5 levels based on clinical and diagnostic interview, level of stutter and diagnostic model of Taghizadeh which clinical pre-test (filming) and between-test and post-test (filming) were carried out during 3 stages. The results of Freedman Parametric test indicated that the average of scores in the stage of pre-treatment (1.02) had significant difference with the stages of post-treatment (2.42) and follow-up (2.56). Hence it can be expressed at 99% confidence level that treatment sessions have great impact on treatment of stuttering disorder. The result of the present research deemed the treatment role of Taghizadeh Model effective and promising. On other words, among 42 patients, 23.8% reached to good therapeutic level and 76.2% reached to perfect therapeutic level. This finding is astonishing all over the world.