ABSTRACT: OBJECTIVE:To investigate the relationship between abdominal ultrasound findings and demographic, historical, and clinical features in children with cystic fibrosis (CF). STUDY DESIGN:Children age 3-12 years with CF without known cirrhosis, were enrolled in a prospective, multicenter study of ultrasound to predict hepatic fibrosis. Consensus ultrasound patterns were assigned by 3 radiologists as normal, heterogeneous, homogeneous, or cirrhosis. Data were derived from direct collection and US or Toronto CF registries. ?(2) or ANOVA were used to compare variables among ultrasound groups and between normal and abnormal. Logistic regression was used to study risk factors for having abnormal ultrasound. RESULTS:Findings in 719 subjects were normal (n = 590, 82.1%), heterogeneous (64, 8.9%), homogeneous (41, 5.7%), and cirrhosis (24, 3.3%). Cirrhosis (P = .0004), homogeneous (P < .0001), and heterogeneous (P = .03) were older than normal. More males were heterogeneous (P = .001). More heterogeneous (15.0%, P = .009) and cirrhosis (25.0%, P = .005) had CF-related diabetes or impaired glucose tolerance vs normal (5.4%). Early infection with Pseudomonas aeruginosa (<2 years old) was associated with a lower risk (OR 0.42, P = .0007) of abnormal. Ursodeoxycholic acid use (OR 3.69, P < .0001) and CF-related diabetes (OR 2.21, P = .019) were associated with increased risk of abnormal. CONCLUSIONS:Unsuspected cirrhosis is seen in 3.3% of young patients with CF, heterogeneous in 8.9%. Abnormal ultrasound is associated with CF-related diabetes, and early P aeruginosa is associated with normal ultrasound. Prospective assessment of these risk factors may identify potential interventional targets. TRIAL REGISTRATION:ClinicalTrials.gov: NCT01144507.