Background: Increasing attention has been given to the transparency of potential conflicts of interest in clinical medicine and biomedical sciences, particularly in journal publishing and science advisory panels. The authors examined the degree and type of financial ties to the pharmaceutical industry of panel members responsible for revisions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Methods: By using multimodal screening techniques the authors investigated the financial ties to the pharmaceutical industry of 170 panel members who contributed to the diagnostic criteria produced for the DSM-IV and the DSM-IV-TR. Results: Of the 170 DSM panel members 95 (56%) had one or more financial associations with companies in the pharmaceutical industry. One hundred percent of the members of the panels on ‘Mood Disorders’ and ‘Schizophrenia and Other Psychotic Disorders’ had financial ties to drug companies. The leading categories of financial interest held by panel members were research funding (42%), consultancies (22%) and speakers bureau (16%). Conclusions: Our inquiry into the relationships between DSM panel members and the pharmaceutical industry demonstrates that there are strong financial ties between the industry and those who are responsible for developing and modifying the diagnostic criteria for mental illness. The connections are especially strong in those diagnostic areas where drugs are the first line of treatment for mental disorders. Full disclosure by DSM panel members of their financial relationships with for-profit entities that manufacture drugs used in the treatment of mental illness is recommended.