Background: Upper extremity is exposed to injuries with physical, mental, social and economic consequences. Objectives: The aim of this research is to study the prevalence and types of personality disorders in patients with upper extremity trauma. Methods: We included all patients with upper extremity trauma in a three-month period. The Millon Test was filled by all candidates with a clinical psychologist and psychometric supervision. Results were analyzed statistically. Results: 202 male patients participated with age range of 14 to 70 years-old, amongst whom 41.4% had personality disorders. The prevalence of personality disorder in violence and self-injury groups was 72.7% and 39.3% respectively in the group of industrial accidents, which showed a significant difference (P = 0.003). Avoidant personality disorders (P = 001), narcissistic (P = 0.003), antisocial (P = 0.002), borderline (P = 0.001) passive aggressive (P = 0.002) were significantly more common in violence and self-injury groups. Conclusions: The present study revealed that the prevalence of personality disorder in patients with upper extremity injuries is more than that in the society. Due to the high rate of personality disorder in hand trauma victims, routine psychological evaluation of these patients is warranted.