Introduction: Cognitive factors are considered extremely important in stuttering. This study aims at examining the effectiveness of mind simulation on psychological symptoms and mental capabilities in adults who stutter. Method: This study was a quasi-experimental research, with two groups (experimental and control group), and it consisted of two pre-test and post-test stages. The research population was all 33 females from stuttering disorder that were clients of speech-therapy centers including in 2019. The final number of samples reached 30 individuals, who were selected by simple random sampling method and were divided into two control and experimental groups. The package of Stuttering Anxiety Questionnaire, Self-esteem Measurement, Self-concept Measurement and Social Communication Measurement were used. Multivariate covariance analysis and SPSS software were used to analyze the data. Results: In general, the findings indicated a significant difference between the data obtained from pre- and post-test average score of the two groups in terms of self-concept, self-esteem, social interactions and anxiety involved in the mind simulation process. Conclusion: The current mind simulation methods have a considerable impact on the psychological symptoms and mental capabilities of adults suffering from stuttering, which can be used as an effective method to improve stuttering.