Background : Research into the relationship between, gender identity disorder and psychiatric problems has shown contradictory results. Aims : To investigate psychiatric problems in adults fulfilling DSM-IV-TR criteria for a diagnosis of gender identity disorder. Method : Data were collected within the European Network for the Investigation of Gender Incongruence using the Mini International Neuropsychiatric Interview - Plus and the Structured Clinical Interview for DSM-IV Axis II Disorders (n = 305). Results : In 38% of the individuals with gender identity disorder a current DSM-IV-TR Axis I diagnosis was found, mainly affective disorders and anxiety disorders. Furthermore, almost 70% had a current and lifetime diagnosis. All four countries showed a similar prevalence, except for affective and anxiety disorders, and no difference was found between individuals with early-onset and late-onset disorder. An Axis II diagnosis was found in 15% of all individuals with gender identity disorder, which is comparable to the general population. Conclusions : People with gender identity disorder show more psychiatric problems than the general population; mostly affective and anxiety problems are found.