BACKGROUND: As a extremely traumatic experience, captivity may cause other mental disorders in addition to posttraumatic stress disorder, which is highly prevalent among ex-prisoners of war, and which often occurs in comorbidity with at least one other mental disorder. This objective of this study is to identify the incidence of comorbid mental disorders in Homeland war veterans ex-prisoners of war affected by posttraumatic stress disorder, as well as to identify the factors that influenced psychiatric comorbidity. SUBJECTS AND METHODS: The study sample comprised 264 subjects, all of whom were Croatian Homeland War veterans with combat experience in the defence of the Republic of Croatia, and all of whom fulfilled clinical criteria for posttraumatic stress disorder at the time of the study. The subjects were divided into two groups: the experimental group was composed of ex-prisoners of war, and the control group of veterans who had never been prisoners of war. The methods of sociodemographic questionnaire, posttraumatic stress disorder self-report checklist and the Harvard Trauma Questionnaire were used in the study. Psychiatric comorbidity data were retrieved from the subjects' anamnesis and medical records. RESULTS: The results showed that ex-prisoners of war were exposed to a statistically much higher number of traumatic events, and had a significantly higher total number of psychiatric comorbidities (p<0.01) than the control group. The incidence of acute and transient psychotic disorders, generalized anxiety disorders and psychological and behavioural factors associated with disorders or diseases classified elsewhere was significantly higher among ex-prisoners of war. There was no statistically significant difference in overall posttraumatic stress disorder intensity between the two groups (p<0.05). CONCLUSIONS: The results of the study confirm our hypothesis that the incidence of psychiatric comorbidity is higher in ex-prisoners of war.