We studied Restless Legs Syndrome (RLS) and nocturnal myoclonus (NM) in 9 patients before and after carbamazepine treatment, to verify the correlation between improvement of RLS and modification of NM pattern during sleep. Although CBZ proved effective in the treatment of RLS, it did not modify the pattern of nocturnal myoclonus and its relationship to arousal during sleep. The efficacy of CBZ on RLS may be due to other properties of the drug rather than to the effect on nocturnal sleep: reduction of sleep latency and wakefulness after sleep onset.