An 8-year-old female with pancreatic-insufficiency cystic fibrosis presented with recurrent pharyngitis, and reduction in body mass index and height velocity during the previous 2 years. Her symptoms (eg, snoring and restless sleep) suggested obstructive sleep apnea, and physical examination revealed tonsillar hypertrophy. While her respiratory disturbance index on nocturnal polysomnography was normal, there was evidence of prolonged periods of snoring, associated with hypercapnia. Adenotonsillectomy decreased the snoring, improved her sleep, and in the 18-month follow-up period she had substantial weight-gain and growth improvement. This case demonstrates that adenotonsillar hypertrophy associated with recurrent pharyngitis and primary snoring might hinder growth in a patient with cystic fibrosis.