The purpose of this study was to evaluate a 4-month dual diagnosis inpatient treatment program that was based on integrative models for patients with substance use and psychiatric disorders. At intake and at 1-year follow-up, dual diagnosis patients (N = 52) were assessed on housing and subsistence level, substance use and psychiatric symptoms. At 1-year follow-up, dual diagnosis patients reported a higher level of housing and subsistence, and less intensive psychiatric symptoms. No change occurred on frequencies of substance use. General improvement may occur even if psychotropic substances are used. Controlled studies are needed on extended inpatient treatment for dual diagnosis patients and outcomes in longer follow-ups.