Andersen-Tawil syndrome (ATS), a rare autosomal dominant disorder, is characterized by periodic paralysis, dysmorphic features and cardiac arrhythmias. This syndrome is caused by mutations of KCNJ2 gene, which encodes inward rectifying potassium channel. Here, we report an 18-year-old girl who was presented with life-threatening cardiac arrhythmia and acute respiratory distress. She was diagnosed with ATS, based on dysmorphic features, ventricular arrhythmia, and periodic paralysis. This is the first case to be reported in Korea who experienced a fatal cardiac arrest and respiratory failure caused by ATS.