Background: Early recognition and prevention of common childhood illnesses are essential to reduce morbidity and mortality among children under five. Aim: To assess parental knowledge and preventive practices related to childhood illnesses in Mongolia. Materials and Methods: A cross-sectional study was conducted among 175 parents and caregivers of children aged 0–59 months attending primary health care facilities in urban and rural areas. Data were collected using structured interviews assessing knowledge of general danger signs, prevention of diarrhea and respiratory illnesses, household environmental risk factors, and injury prevention. Descriptive statistics and comparative analyses were performed, with statistical sig nificance set at p<0.05. Results: Urban caregivers identified significantly more general danger signs than rural caregivers (mean 5.3 vs 3.2; p<0.001). Knowledge levels did not differ between caregivers of ill and healthy children. Preventive practices related to diarrhea showed no significant association with child illness status. Rural households reported higher exposure to indoor air pollution from solid fuel use. Injuries requiring medical attention were reported in 22.9% of children, with no signifi cant differences in injury prevention knowledge. Conclusion Parental knowledge varied by place of residence rather than child health status, underscoring the need for context-specific health education within primary health care services, particularly in rural settings.