Introduction. It is well known that Bipolar Disorder subjects have high rates of substance use, with rates of 65% for abuse or dependence in comparison with general population (25%) Objective. To assess comorbidity with substance abuse or dependence in patients treated at Instituto Nacional de Psiquiatría “Ramón de la Fuente” and its influence in clinical course of bipolar disorder. Methods. We assessed a 100 sample of Bipolar I and II subjects with or without history of substance abuse or dependence. We used International Neuropsychiatric Evaluation (MINI) to detect substance use, abuse or dependence. Results. 85% of the sample corresponded to Bipolar I. 15% were BD II, 63% were female, onset of BD was at 26.8 years old. The prevalence of substance disorders was of 62% (27% substance abuse, 19% alcohol dependence and 16% substance dependence). Comorbid Anxiety disorder was the clinical characteristic more related with substance abuse or dependence, 27% of this group met DSM-IV criteria. Cannabis was the substance more used by BD subjects (11%) followed by Cocaine in 6%. BD patients with substance abuse or dependence had a higher prevalence of psychiatric comorbidities vs. BD subjects without substance disorders (1 vs. 0.29). 70.4% of the sample with substance disorder had history of inpatient treatment with an average of 2 hospitalizations. Conclusions. Prevalence of substance abuse or dependence and anxiety disorders in bipolar subjects is higher than in other psychiatric and general samples. This comorbidity has been associated with a worse clinical course for Bipolar Disorder.