Mean manganese superoxide dismutase (Mn-SOD) concentrations in the serum of patients suffering from alcohol dependence is almost twice as high as in serum of non-dependent controls. In order to investigate the time course of this parameter during abstinence, we determined it at different time points. Patients had mean Mn-SOD serum concentrations (±S.D.) of 150.4 ± 76.3, 121.1 ± 40.7, 94.6 ± 37.8 μg/ml at 1, 10 and 40 days after abstinence compared to 76.3 ± 16.9 μg/ml as mean Mn-SOD value in the control group. Although the Mn-SOD concentration tended to normalise during abstinence, the differences between index and control group remained significant up to the last measurement at day 40.