Disturbances of noradrenaline neurotransmission probably play a role in the pathogenesis of bipolar affective disorder. The purpose of the present study was searching for an association between 1287 A/G polymorphism of noradrenaline transporter gene (nroepinephine transporter - NET) and a prophylactic effect of lithium carbonate in patients with bipolar affective illness. The study included 90 subjects (52 women and 38 men) with bipolar affective illness. The mean age of the patients was 52 ± 12 years and the duration of lithium therapy was 14,6 ± 7,3 years. Serum lithium concentration in those patients was in the range of 0,5 to 0,8 mmol/l. Patients were divided into three groups, depending on the efficacy of lithium carbonate prophylaxis: excellent lithium responders, partial lithium responders and lithium non-responders. In the group of investigated patients, no relationship between the quality of lithium prophylactic effect and the studied polymorphism of NET gene was found.