This was a prospective open study that examined the quantitative and qualitative analysis of hepatobiliary scintigraphy (DISIDA) in detecting liver involvement in cystic fibrosis (CF). Forty-four adult and pediatric patients (median age, 12.1 years; range, 1.1-36.3 years) were divided into three groups: group 1, no evidence of liver involvement (n = 8); group 2, biochemical evidence of liver involvement on two or more occasions (n = 26); and group 3, clinical evidence of liver disease (n = 10). In groups 1 and 2, the most common qualitative scintigraphic finding was focal intrahepatic retention of tracer (26/34 patients, 12 of whom had normal findings on ultrasonography). This finding corresponds to focal cholestasis and may warrant treatment with the choleretic agent ursodeoxycholic acid (UDCA). In the group 3 patients, the abnormal qualitative scintigraphic appearances (heterogeneous uptake of tracer and nodular liver outline) added little to the findings on ultrasonography; however, these patients had a prolonged mean hepatic clearance time compared with those in groups 1 and 2 (one-way ANOVA; P < .015). It is proposed that scintigraphy with DISIDA has a role in the detection of early liver involvement in cystic fibrosis.