The objective of this analysis was to determine the association between childhood obesity and hospital length of stay (LOS) utilizing the Florida Agency for Health Care Administration (AHCA) database. Children aged 618 years old who were admitted to Florida hospitals in the United States during 2005 with a primary or secondary diagnosis of overweight, obesity, or morbid obesity were coded as "obese" (n=2257). Children without any of these three diagnoses were coded as "non-obese" (n=69,180). Due to the small number of overweight or obese children under age 6, the analyses were restricted to children between 6 and 18 years old. The adjusted mean LOS (days) was compared between obese and non-obese groups. Multivariable logistic regression analyses identified correlates of a long LOS (>= 3 days). Of 2257 obese children, 80% were 12-18 years old, 59% were girls, and 51% were insured by Medicaid. Among non-obese children, the proportions were 66% (12-18 years), 47% (girls), and 42% (Medicaid beneficiaries). Mean LOS was greater in obese (3.2 days) than in non-obese (2.8 days) children (p<.001). Obesity remained associated with LOS after adjusting for age, sex, race, insurance status, and hospital charges (odds ratio, 1.4; 95% confidence interval, 1.3-1.6). Proportions of mental health diagnosis in obese (11.8%) children were higher than that of non-obese (3.8%) children. Children with a primary or secondary diagnosis of overweight, obesity, or morbid obesity require longer hospital stays than do children without these diagnoses. Obesity prevention programs could potentially reduce hospital stays and their associated costs. (C) 2010 Elsevier Ireland Ltd. All rights reserved.