Wilson's disease presents as a classical hereditary syndrome of clinical and biochemical abnormalities. Life-long treatment with copper-chelating agents may dramatically alter the subsequent course and outcome. Hence, considerable attention has been drawn to early recognition and treatment. Since the presentation of Wilson's disease may simulate chronic active hepatitis of unknown etiology, it has been emphasized that the diagnosis of the genetic disorder should be suspected and excluded in this clinical setting. In this report we describe the difficulties encountered in the evaluation of a patient with non-Wilsonian chronic active hepatitis and low serum ceruloplasmin levels. This case illustrates that the distinction between the Wilson's disease homozygote and the hypoceruloplasminemic patient with idiopathic chronic active hepatitis may be difficult to establish and requires a critical evaluation of data to avoid diagnostic pitfalls.