Background: Diagnosing undernutrition in hospitalized pediatric populations is crucial to provide timely nutrition interventions. Handgrip strength (HGS), a measurement of muscle function, is a reliable indicator of undernutrition. However, limited research exists on HGS in hospitalized pediatric patients. The primary aim of this study was to determine if HGS differed between hospitalized children within 48 hours of admission and nonhospitalized children. A secondary purpose was to describe the association of HGS with height, weight, body mass index (BMI), mid upper arm circumference (MUAC), activity level, disease severity, nutrition risk, and nutrition intervention. Methods: One hundred nine hospitalized and 110 nonhospitalized patients aged 6–14 years participated in this cross-sectional nonequivalent control group design study. Weight, height, MUAC, and HGS were measured within 48 hours of hospital admission for the hospitalized group or immediately following a well-child visit for the control group. Results: Based on analysis of covariance, the HGS was estimated to be 12.4 ± 0.37 kgF (mean ± SE) for hospitalized subjects and 13.1 ± 0.37 for nonhospitalized subjects (P = .2053). HGS was associated with age (P < .0001), height (P < .0001), dominant hand (P < .0001), and MUAC z scores (P = .0462). Conclusion: HGS was not significantly different between hospitalized and nonhospitalized participants, although anthropometric measurements were similar between groups. A strong relationship was demonstrated between HGS and BMI and MUAC z scores. Further research is needed that examines serial HGS measurements, feasibility in hospitalized patients, and the association of HGS measurements and nutrition risk.