Eighty patients aged between 20-65 years and suffering from bipolar disease according to DSM IV criteria, were treated with paroxetine for os at the single dosage of 20-40 mg/die. At regular intervals psychometric reagents were administered for the evaluation and the variations in the bipolar disease. Tolerability was excellent and side-effects mild, with a tendency to regress after the second week of therapy. The clinical assessment and the psychometric findings both suggest that paroxetina has a useful action on the bipolar disease.