OBJECTIVE: To determine the association between Hispanic ethnicity and limited English proficiency (LEP) and the rates of appendiceal perforation and advanced radiologic imaging (computed tomography and ultrasound) in children with abdominal pain. STUDY DESIGN: We performed a secondary analysis of a prospective, cross-sectional, multicenter study of children aged 3-18 years presenting with abdominal pain concerning for appendicitis between March 2009 and April 2010 at 10 tertiary care pediatric emergency departments in the US. Appendiceal perforation and advanced imaging rates were compared between ethnic and language proficiency groups using simple and multivariate regression models. RESULTS: Of 2590 patients enrolled, 1001 (38%) had appendicitis, including 36% of non-Hispanics and 44% of Hispanics. In multivariate modeling, Hispanics with LEP had a significantly greater odds of appendiceal perforation (OR, 1.44; 95% CI, 1.20-1.74). Hispanics with LEP with appendiceal perforation of moderate clinical severity were less likely to undergo advanced imaging compared with English-speaking non-Hispanics (OR, 0.64; 95% CI, 0.43-0.95). CONCLUSION: Hispanic ethnicity with LEP is an important risk factor for appendiceal perforation in pediatric patients brought to the emergency department with possible appendicitis. Among patients with moderate clinical severity, Hispanic ethnicity with LEP appears to be associated with lower imaging rates. This effect of English proficiency and Hispanic ethnicity warrants further investigation to understand and overcome barriers, which may lead to increased appendiceal perforation rates and differential diagnostic evaluation.