Aim. To determine if the patients with bipolar affective disorder, after the depressive phase, would exhibit cognitive impairment in remission. Methods. Twenty three euthymic patients with bipolar disorder were matched, on a case-by-case basis, to twenty-one healthy subjects in the control group, for the presence of the symptoms of depression. The patients and the control group were tested with a battery of neuropsychological tests. Results. Impairments were found in the patients compared with the control group in tests of verbal learning and memory and in tests of executive function. Verbal learning and memory, as well as executive functions, did not correlate either with the clinical indices of patients, or with the demographic and baseline clinical measures of depression. Conclusion. Impaired verbal learning and memory and executive functions may represent a trait rather than the state variables in bipolar disorder.