The aims of this study were to examine the associations between psychiatric disorders and pathological gambling (PG) and the clustering of psychiatric disorders in high risk gambler populations. The sample comprised 140 regular gamblers who were recruited from the general public. A variety of self- report and semi structured questionnaires was administered, including the Mini International Neuropsychiatric Interview, The Personality Diagnostic Questionnaire-4th Edition, NORC DSM-IV Screen for Gambling Problems Self- administered and Problem Gambling Severity Index. Axis I and Axis II psychiatric disorders and personality disturbances were found to be more prevalent amongst pathological gamblers than other gamblers with the strongest differences observed for mood and anxiety-related disorders. Almost two-thirds of pathological gamblers reported both an anxiety or mood disorder in conjunction with another type of disorder. These differences between the gambling groups existed even after controlling for gender. The results highlight the high rates of co-morbidity in pathological gamblers in the community and the extent to which anxiety and mood disorders co-existing with other forms of pathology. These results highlight the significant challenges facing treatment services in the treatment of PG and the extent to which this should be treated as the primary disorder.