Human behavior is the internal coordinating responses to an internal and external stimulus 1. Human health is complete physical, mental and social well-being not merely the absence of disease 2, 3. Health care seeking behavior is defined as any action taken by someone to find an appropriate remedy when the child has a health problem or illness 4. Worldwide, around 6.3 million children under the age of five died and most of them could be prevented or treated with access to simple and affordable interventions 5. Childhood illnesses are the major global health problems around the world particularly Asian and African subcontinents 6. Under-five children are the most risk group of all population to be suffered from common childhood illness 5. The global under-5 mortality was 41 per 1000 live births in deaths in 2016 5 and in Ethiopia, the under-5 mortality was 67 deaths per 1,000 in 2016 7.The child is a victim of nutrition, socioeconomic and health factors, which causes malnutrition 8. The delay in the proper seeking of care in modern health facilities contributes to a large number of child deaths throughout the world especially in san Saharan Africa 9, 10. In Ethiopia, under-five mortality was higher among children of poor and non-educated families. Moreover, Advice or treatment from health facility was sought for 31% of children with ARI, 35% of children with fever, and 44% of children with diarrhea 7.The World Health Organization estimates that seeking appropriate medical care could reduce child deaths childhood illness by 20% 11. Health -seeking behaviors is a function not only of the availability of health facilities and other sources of healthcare but also motivation and ability of individuals to seek medical treatment 12.Even though the common childhood illnesses are manageable successfully if timely recognized, facilitation of modern care seeking behavior remained a challenge today 13. Hence early interventions potentially reduce child mortality in developing countries, a large number of children die without ever reaching a health facility and due to delays in seeking care 10. Appropriate care seeking behavior is an important parenting tool in preventing the child from this preventable morbidity and moralities 14. To meet the Sustainable Development Goal (SDG) target one on under-five mortality by 2030 in reducing the number of under-5 deaths by 10 million between 2017 and 2030 6, a rapid progress is needed to increase the community awareness in modern health-seeking behavior.Although Ethiopia has progressed on universal access to standard case management common childhood illnesses, healthcare-seeking behaviors of caregivers for child illness has remained low. Generally, there are some studies on health-seeking behavior in our countries but there is no study conducted to identify modern health-seeking behavior and associated factors in this study area. Therefore the purpose of this study is to assess modern health-seeking behaviors and associated factors among mothers having under five children in Shire town, Northwest Tigray, Ethiopia.