OBJECTIVES: To fully describe patients' characteristics, management patterns, predictive recurrence factors and economic impact of health care attention of bipolar patients population in Spain. The description of the sample of an ongoing cohort study is being presented. METHODS: Prospective observational cohort study with a follow-up of 12 months including consecutive outpatients diagnosed of Bipolar Disorder I or II (DSM-IV-TR), stabilized for at least 2 months, who had at least a mood disorder episode (depression, mania, hypomania or mixed) in the last year.   RESULTS: A total of 571 patients were included, 60.1% women. Mean age was 47.4 years (SD 13.1).  Only 37.5% were active workers, up to 5.4% were having temporal disability leave and 16.2% were permanent disabled for working.  Regarding study disease, 75% were bipolar I and mean time since diagnosis was 12.3 years (SD 10.5), although time since first mood episode compatible with bipolar diagnose was 16.3 years (SD 11.2). Mean mood episode number since disease onset was 10.6 (SD 9.3). Up to 74.1% of patients had been hospitalised during the disease evolution , mean times were 3.6 (SD 3.3). 21.3% of patients have had a suicide attempt. Regarding the baseline evaluation, 29.9% of patients were not free of mood symptoms even being stabilized for at least two months, presenting more than two mania symptoms (10.6%) and more than 2 depression symptoms (18.2%). CONCLUSIONS: Even in the stabilization phase of the disease there is an important symptoms load.  Although depressive symptoms are more frequent than manic symptoms, both subsyndromal symptoms  are present in euthimic bipolar patients. Bipolar disorder is a relevant chronic condition in terms of disease burden, since it affects young people affecting productivity with a high rate of disability. Hospitalisations are needed in almost 75% of patients and more than 3 times during disease evolution (mean 12 years).Further knowledge about potentially preventable factors associated with severity and disease cost and burden would be of extreme value.