Hiccups are a spasmodic contraction of the diaphragm and usually transient phenomenon that affects nearly everyone. When hiccups develop, the patients are administrated antispastic agent, such as baclofen. Baclofen is widely used for the treatment of this spastic movement disorders. Also, baclofen is a gamma-aminobutyric acid (GABA) derivative that induces presynaptic motor neuron inhibition and produces a central antispastic response. Baclofen toxicity is rare and has been reported with intrathecal pump and orally administered baclofen, particularly in patients with poor renal function. Herein, we report two cases of encephalopathy in hemodialysis and peritoneal dialysis patients who received low doses of baclofen for persistent hiccups.