Objective: Mental disorders and early trauma are highly prevalent in female inmates. Brain-derived neurotrophic factor (BDNF) plays an important role in learning, memory processes, and mood regulation. The aim of this study was to evaluate the relationship between serum BDNF levels and mental disorders among imprisoned women as compared with age-and education-matched controls. Methods: A consecutively recruited sample of 18 female prisoners with mental disorders was assessed for sociodemographic, criminal, and clinical variables using standardized instruments, the Mini International Neuropsychiatric Interview Plus (MINI Plus), and serum BDNF levels. Results: High rates of childhood sexual abuse and posttraumatic stress disorder (PTSD) were found in the group of forensic patients. Serum BDNF levels in the forensic group did not differ from those of healthy controls, and were significantly higher when compared with those of women with mental disorders hospitalized in a general hospital. Conclusion: Elevated serum BDNF levels were found in imprisoned women. The results of this study may suggest neurobiological mechanisms similar to those seen in previous clinical and preclinical studies showing the involvement of BDNF in the pathophysiology of PTSD.