BACKGROUND Body mass index (BMI) is used to determine nutrition status in children with cystic fibrosis (CF); however, lean body mass (LBM) is more strongly associated with pulmonary function. Handgrip strength (HGS) measures muscle function and is reflective of LBM. The aims of this study were to assess relationships among HGS, nutrition status, and pulmonary function; changes in HGS posthospitalization; and any relationship between HGS and nutrient intake. METHODS Twenty-three children with CF aged 6-18 years participated. BMI z scores, nutrition risk scores, and pulmonary function were assessed about 5 months before, days 5-7 of hospitalization, and about 6 weeks posthospitalization. HGS z scores and arm anthropometrics were measured during and after hospitalization. Nutrient intakes were assessed during hospitalization. RESULTS Mean HGS z score at hospitalization was -1.95 ± 0.92 and posthospitalization was -1.59 ± 1.06 (P = .007). Mean BMI z score prehospitalization was -0.17 ± 0.63, at hospitalization was -0.09 ± 0.64, and posthospitalization was 0.06 ± 0.54 (P = .065). Mean forced expiratory volume in 1 second (FEV1 ) prehospitalization was 93.52 ± 17.35, at hospitalization was 85.65 ± 21.57, and posthospitalization was 95.63 ± 18.18 (P = .001). No significant relationship was found between HGS z scores and BMI z scores (P = .892) or HGS z scores and FEV1 (P = .340). CONCLUSIONS HGS z scores and FEV1 significantly increased at follow-up. HGS z scores were lower than the standard even though mean BMI z scores classified participants as normal nutrition status.