From many decades efficacy of lithium salts, as mood stabilizers, has been largely recognized, but their tolerability, in particular during intermediate or long-term treatments is still discussed. The most frequently described side effects can affect several organs. Aim of the study was to evaluate lithium carbonate tolerability after a "brief" (1 month-4 years), "intermediate" (5-9 years) and "longterm" (10-21 years) treatment of patients affected by Bipolar Disorders (BD). 27 patients (14 males, 13 females), aged from 20 to 78 years (mean 49.03 years +/- 14.61 SD), affected by BD, type I, according to DSM IV criteria were included into the study. Our data suggest a good tolerability of lithium salts without significant differences among the three different periods of treatment.