Background:The under-five children are a vulnerable age group; their mortality reflecting a country's overall development. Timely and appropriate healthcare seeking behavior, if practiced by caregivers, can have a significant impact on survival. The slum dwellers have poor health-seeking behavior due to their lower socioeconomic status, prevailing malnutrition, poor immunization status, overcrowding, poor sanitation, personal and cultural practices, beliefs, and attitude toward healthcare providers.Objectives:(1) To assess the health-seeking behavior among caregivers of under-five children during acute childhood illness (2) To find out the factors associated with their treatment-seeking behavior.Materials and Methods:A community-based cross-sectional study, among 260 caregivers, in the field practice area of Urban Health and Training Centre of a medical college was undertaken from September 1, 2016 to February 28, 2017, using a pretested semistructured questionnaire after obtaining a list of under-fives from the female health worker.Results:In total, 260 caregivers with mean of 26.61 ± 4.31 years participated in the study, 77.69% reported of some health morbidity. Around 21.92% of the caregivers gave primary care at home, 33.46% visited a chemist, and 33.08% attended health facility nearby. About 79.23% sought healthcare immediately following illness. Of the remaining 20.77% who did not seek medical advice, 75.93% used home remedies. Significant association was found between the age of the mother, educational status of the mother, religion, birth order of the child and socioeconomic status of the caregivers, and appropriate treatment seeking behavior during an episode of acute illness.Conclusion:This study attempted to identify health-seeking behavior of caregivers for children under-five and the determinants of appropriate treatment-seeking behavior. The knowledge of signs and symptoms of ill-health can reduce morbidity and mortality; however, continuous education of caregivers for recognition of symptoms and the need to seek appropriate medical care is needed. Government facility was the preferred choice for the population in the sampled slum. Treatment-seeking behavior was good among the respondents with majority having appropriate behavior. Measures can be taken to help promote awareness among those who did not have appropriate treatment seeking behavior.