Objective: This research project set out to evaluate the prevalence of substance abuse disorders in individuals seeking support for mental illness. It also aimed to evaluate the satisfaction of those individuals in relation to the treatment and support they are receiving for substance abuse. Design: A questionnaire with two sections was used. Section one included 27 questions selected from the Addiction Severity Index. Section two was composed of seven open ended questions and an area for participants to write any additional comments they wanted to express. Subjects: Forty-seven participants completed and returned the questionnaires in full. Response rate (39.1 %). These participants were all current members of Schizophrenia Ireland from the Dublin, Cork and Kerry branches. Results: 46.8% of participants reported substance abuse problems in their lifetime. In addition to this it was found that there is a significant correlation between the presence of dual diagnosis and the dissatisfaction with services. Also the results demonstrated that 56.5% of those who reported past substance abuse reported past treatment for substance abuse and that of that population 53.8% reported past treatment in the form of detoxification only. Conclusion: A significant amount of individuals with diagnosed mental illness experience problems with substance abuse 46.8%. A significant amount of these cases are gone untreated. Individuals with dual diagnosis view addiction and mental health treatment and support services as insufficient in catering for their needs.