Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 18 2 2024 01 23 199 208 Maedeh Salehi Darjani Department of Speech Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Rahim Shahbodaghi Department of Speech Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Shohreh Jalaie Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. 2022 07 03 2023 01 25 Introduction: Fluent speech requires executive functions to identify, inhibit, and modify speech interruptions to continuously regulate the speech process. The current study aims to examine the executive functions in adults who stutter (AWS) and adults who do not stutter (AWNS). We also examined the relationship between executive functions and stuttering severity. Materials and Methods: This research is a cross-sectional descriptive-analytic study. The participants included 32 AWS (Mean±SD of age=28±6.79) divided into three groups of mild, moderate, and severe severity and 32 AWNS (Mean±SD of age=28.57±6.53). Selected tests from the Delis-Kaplan executive function system (D-KEFS) were used to assess executive function domains. Results: The results of this study showed that AWS performed significantly lower than AWNS in working memory (P=0.009), problem-solving and planning (P<0.001), verbal cognitive flexibility (shifting) (P<0.001), and verbal inhibitory control (P<0.001). The results also showed no difference between AWS and AWNS in non-verbal inhibition, shifting, and reasoning. Furthermore, a significant relationship was observed between stuttering severity and executive function domains. Conclusion: This study showed that executive function skills are affected in AWS and should be considered in the rehabilitation programs of AWS. https://jmr.tums.ac.ir/index.php/jmr/article/view/699