Aim <p>Muscle tension dysphonia is a functional voice disorder. In addition to physical characteristics, the disorder can impose negative emotional and personality effects on individuals. Considering the effects of voice disorders on acoustic characteristics, as well as psychological and personality characteristics of individuals, the current research was aimed at investigating the relationship between personality and psychological characteristics and vocal characteristics in patients with functional voice disorders and healthy individuals.</p> Subject and methods <p>The present study included 175 patients suffering from muscle tension dysphonia and 125 healthy individuals. To assess the psychological traits of the participants, the study used the Persian version of the psychological Symptom Checklist-90 (SCL-90). The Persian version of the NEO Five-Factor Inventory (NEO-FFI) was utilized to examine personality traits, while the dysphonia severity index (DSI) was employed to measure the voice characteristics of the participants.</p> Results <p>Comparing the personality characteristics of the healthy and patient groups, the results revealed a significant difference in neuroticism, extraversion, and agreeableness. However, no significant difference was found between the two groups for openness to experience or conscientiousness. A comparison of healthy and functional voice disorder groups showed that the mean of all psychological variables in the group with functional voice disorder was significantly higher. No significant relationship was observed for psychological characteristics and the DSI in the patient and healthy groups.</p> Conclusion <p>Our observation of the patients demonstrates that, in addition to the physical aspects (external laryngeal muscle cramps), psychological-personality factors are also important and may affect the treatment process.</p>