Wilson disease (WD) is one of the most common inborn errors of metabolism characterized by degenerative changes in the brain, liver and kidney dysfunction, and Kayser-Fleischer rings due to toxic accumulation of copper. We investigated a Korean family with WD occurred in two consecutive generations. The proband, a 14-yr-old girl, was noticed to have abnormal liver function on a routine health examination at school and was diagnosed of having WD by further laboratory tests and liverbiopsy. Molecular geneticanalysis of ATP7B gene demonstrated that she was homozygous for Ala-874Val mutation, one of the three common mutations in Korean patients with WD. Further study for her family members revealed that the proband's father, a paternal uncle, and the youngest sister were compound heterozygous for Ala874Val and Asn1270Ser mutations of the ATP7B gene. In addition, the proband's mother and a younger sister were heterozygous carriers of Ala874Val mutation. Therefore, WD occurred in two consecutive generations due to a WD father and a heterozygous mother. Actually, abnormal results on liver function tests were found in the proband's father and a paternal uncle a few years ago but a diagnosis of WD has not been made. Therefore, although WD has been thought to be uncommon in Korea, it should be considered in a differential diagnosis of patients exhibiting abnormal liver function with unknown cause.