A case of acute akathisia induced by lithium treatment is described. Since lithium administration leads to activation of serotonergic neurotransmission, the 5-HT2A/2C and 5-HT3 antagonist mianserin was added as a possible anti-akathitic agent. Mianserin treatment (15 mg/day at 21.00 h) resulted in amelioration of the lithium-induced akathisia.