Background: Cystic fibrosis (CF) is an autosomal recessive disorder affecting the exocrine functions of many organs including the pancreas. Clinical and laboratory recognition of pancreatic insufficiency is important for proper treatment. Early radiologic detection of pancreatic pathologic changes can help better evaluation. Objectives: To correlate exocrine pancreatic function with pancreatic ultrasound changes in CF children. Methods: This was a prospective cross-sectional study to assess the exocrine pancreatic function by measuring fecal elastase-1 (FE-1) level and doing pancreatic ultrasound for CF patients. Results: A total of 30 CF patients with age range from 3 months to 10 years were included in the study. They were categorized into three age groups; below one year, from 1 to 4 years and above 4 years old. None of our cases was exocrine pancreatic sufficient regarding FE-1 level and most of them (86.7%) had severe fecal elastase deficiency. Before 1 year of age there was no detected abnormal ultrasound findings in pancreas; only 8 older patients had abnormal US detected as hyper-echogenicity of pancreas. Abnormal US was more detected among patients with severe pancreatic insufficiency. The sensitivity of ability of fecal elastase level to predict abnormal ultrasound was 80%, with 84% specificity at cut of point 15.2 µg/g. Conclusions: Fecal-elastase-1 measurement in cystic fibrosis children can diagnose the exocrine pancreatic insufficiency even without clinical manifestations of steatorrhea. FE-1 level can predict pathologic changes of pancreas detected by transabdominal ultrasound.