['To evaluate the relationship between nutritional status early in life and the timing and velocity of height growth, lung function, complications of cystic fibrosis, and survival.', 'Prospective, observational study using data from the Cystic Fibrosis Foundation Registry (US) for patients born between 1989 and 1992 (n\xa0=\xa03142).', 'Weight-for-age percentile (WAP) at 4 years of age was positively associated with height-for-age percentiles throughout childhood. Age 4 years WAP >10% was associated with better lung function from 6-18 years of age. In boys and girls with current WAP >50%, peak pubertal height velocities approximated but remained lower than that of the healthy reference population. By age 18 years, patients with an age 4 years WAP >50% suffered fewer acute pulmonary exacerbations, spent fewer days in the hospital, and had lower rates of impaired glucose tolerance or diabetes. Patients attaining higher age 4 years WAP and height-for-age percentiles had a survival advantage throughout childhood.'] Is better nutritional status in early childhood associated with improved clinical outcomes and survival in patients with cystic fibrosis?