Approximately 10 million individuals in the United States have co-occurring or dual diagnosis mental and addictive disorders. Often, the two co-occurring illness are a form of substance abuse or dependency and a severe or persistent clinical syndrome such as depression, schizophrenia, or bipolar disorder. The heterogeneity of the co-occurring addictive and mental disordered population needs to be taken into account when treatment strategies are developed. Treatment facilitators at the First Judicial Department of Correctional Services in Waterloo, IA, recognized that many of their female clients were suffering from co-occurring disorders and needed gender-specific residential and community-based programs to address their special needs. The close association among co-occurring disorders, victimization, and homelessness indicates that both residential needs and victimization must be addressed in treated women with co-occurring disorders, yet there are many barriers to the development of effective treatments for the co-occurring disorders population. Effective treatment for this population should contain individualized programs to effectively address symptom severity and skills deficiency, treatment interventions in phases, individualized service plans, and varied treatment approaches and linkages. Iowa’s Dual Diagnosis Program is displaying success rates above the norm. Confidentially issues, parallel treatments, funding limitations, and a lack of gender specific research are barriers to providing effective treatment to the co-occurring disorders population. Despite barriers to the Dual Diagnosis Program, treatment facilitators are planning to keep the program going, and considering additional treatment options and solutions to provide a wide range of gender-specific treatment options to the co-occurring disorders population.