IntroductionAt least one-half of patients in substance use treatment have been diagnosed with comorbid psychiatric disorders. High prevalence of severe mental disorders co-occurring with substance use have been described. Harm reduction refers to policies, programs and practices that aim to reduce the harms associated with the use of illegal drugs in people unable or unwilling to stop.ObjectivesTo describe attendance and integration of patients with substance use disorders in a harm reduction program, to psychiatric treatment.AimsFind the importance and profitability of Harm Reduction Programs as an access door to psychiatric treatment in people with drug addiction.MethodsData was gathered from the first interview survey made to patients that contacted the Harm Reduction Program or attending the Outpatient Drug Clinic Vall d’Hebron in Barcelona between January 2005 until September 2010.ResultsA total of 348 patients (males = 71%, European community origin = 92%, mean age = 28,18 years). 63,8% of patients were under medical and psychiatric treatments, 55,4% attended the Methadone Maintenance Program, 7,4% other psychiatric treatments, and other treatments without specification 30,7%. The residential status was: 38% squatters, homeless 9,7%, hostel 3,4%, home 43%, lodging 2%, others 3%.ConclusionsMore than fifty percent of harm reduction program patient's were in a psychiatric treatment, it is an advantage that in the outpatient drug clinic of Vall d’Hebron both programs are included: harm reduction and psychiatric assessment. Access to integral treatment is important for people with drug problems, but many people with drug problems are unable or unwilling to get treatments.