Cystic fibrosis is a genetic disorder characterized by chronic obstructive pulmonary disease, pancreatic exocrine deficiency, and abnormally high sweat electrolyte concentrations. Less frequently, the presenting features in infants may include edema, anemia, hypoproteinemia, and acrodermatitis enteropathica. Liver involvement may produce hepatomegaly and mild elevation of transaminases. This clinical symptom usually presents within the first 6 months of life and is associated with a high morbidity and mortality. Early recognition and institution of appropriate nutritional supplementation and pancreatic enzymes is essential to improve outcome. Since the sweat test may be falsely negative, emergency physicians must maintain a high index of suspicion to make the diagnosis of cystic fibrosis in an infant who presents with edema, anemia, hypoproteinemia, and acrodermatitis enteropathica.