Cystic fibrosis (CF) is a multisystemic life-limiting genetic disorder, primarily affecting respiratory functioning. Most patients with CF are diagnosed by 2 years of age, and the current median predicted survival rate is 37.4 years old, with 95% of patients dying from complications related to pulmonary infection. Given the chronic, progressive, and disabling nature of CF, multiple treatments are prescribed, most on a daily basis. Thus, this illness requires children, with the aid of their families, to adopt multiple health-related behaviors in addition to managing more typical developmental demands. The morbidity and mortality factors pose cognitive, emotional, and behavioral challenges for many children with CF and their families. This article applies a developmental perspective to describing the psychosocial factors affecting psychological adjustment and health-related behaviors relevant to infants, preschool and school-age children, and adolescents with CF. Topics particularly pertinent to developmental periods and medical milestones are noted, with clinical implications highlighted.