Aim. The main objective of the presented study was to investigate relationships between lifetime comorbidity in bipolar disorder to demographic and clinical variables and level of functioning in current remission. The prevalence of comorbidity and gender and bipolar subtype differences were also assessed. Subjects and methods. Seventy three bipolar I or II outpatients in remission (Hamilton Depression Rating Scale < 9, Young Mania Rating Scale < 7) were assessed by means of the Composite International Diagnostic Interview (CIDI) in order to detect possible anxiety and substance use comorbid diagnoses. The sample was split according to the presence of different classes of comorbid disorders and the groups were compared. Results. Lifetime psychiatric comorbidity (anxiety and substance use disorders) was 71.2%. The only significant differences between sexes were found in general substance use disorders, alcohol and nicotine use disorder comorbidities. Only panic disorder with or without agoraphobia and nicotine use disorders were significantly more prevalent in BP I than in BP II. Significant differences between non-comorbid group and comorbid groups were found in some investigated variables. Conclusions. Lifetime psychiatric comorbidity is a common phenomenon in bipolar disorder associated with some demographic and clinical variables.