Aims & Objectives: Children in resource-limited settings (RLS) bear a disproportionate burden of mortality. Most life-threatening pediatric illnesses can be managed with basic critical care interventions but, in RLS, are often managed without adequate resources and outside of formal intensive care units. This study aimed to estimate the prevalence and etiology of P-ACI amongst children presenting to RLS hospitals. Methods: This is a prospective, multinational prevalence study of acutely ill or injured children (28 days-14 years) who presented to RLS hospitals. We excluded children with non-acute presentations. We measured prevalence of P-ACI and followed admitted subjects for hospital outcomes. We used descriptive statistics to summarize site- and population-level data by sociodemographic category and multivariable logistic regression to determine whether sociodemographic category was independently associated with P-ACI. Results: The study included 46 sites from 19 countries (N=7457 subjects). P-ACI prevalence was 13% (N=986/7457). In a multivariable model, lower sociodemographic category was associated with P-ACI (adjusted odds ratio 1.9 [95%CI 1.5-2.2]). The most common P-ACI diagnoses were pneumonia (N=152/986 [15%]), sepsis/septic shock (N=102/986 [10%]), and malaria (N=95/986 [10%]). Cohort mortality was 1% (N=68/7457) and most deaths occurred within 48-hours of presentation (N=47/68 [69%]). All-cause mortality (2.5%) and P-ACI prevalence (29%) were highest in the lowest sociodemographic category. Conclusions: P-ACI is common in RLS hospitals and frequently associated with infections that can be managed with basic critical care services. A coordinated global effort is needed to increase high-quality, basic pediatric critical care services in RLS hospitals to prevent mortality and care for children with life-threatening conditions. Keywords: Resource-limited settings, low- and middle-income countries, paediatrics, child health, global health