OBJECTIVE: Persistent neurocognitive deficits have been described in bipolar mood disorder. As far as we are aware, no study have examined whether the cognitive impairment is presented in the same way in a Brazilian sample. METHOD: Cognitive function of 66 patients with bipolar disorder (32 with depressive symptoms and 34 euthymic) and 28 healthy subjects was examined using a complete cognitive battery. RESULTS: Patients with bipolar disorder presented a significantly poorer performance in eight of the 12 subtests when compared to healthy subjects. There was no significant difference between the subgroups of patients. These patients showed impairment in both verbal and non-verbal cognitive function. CONCLUSION: Cognitive impairment was found in both groups of patients with bipolar disorder. The findings described here suggest an overall impairment of cognitive function, independent of mood symptoms. This is in line with data showing that cognitive deficits may be a persistent characteristic of bipolar disorder.