Background: World Health Organization recommended priority lifesaving medicines for under-five children are those medicines respond to the leading cause of under-five morbidity and mortality. Thus, they should be available within the context of functioning health systems at all times. However, the availability of these medicines and its determinants are not well studied in Ethiopia in general and in primary public health facilities of Amhara region in particular. Objective: This study assesses the availability and associated factors of the WHO-recommended priority lifesaving medicines for under-five children in primary public health facilities of Amhara region Methods: A cross-sectional study design was conducted in 98 health centers and 22 primary hospitals in Amhara region, Ethiopia. Facilities were selected with simple random sampling technique. The data were collected through pretested and structured questionnaire and data were entered with EPI info and exported to SPSS version23 statistical software for analysis. Binary logistic regressions were used for the study. Results: The availability of the majority of medicines in primary public health facilities of Amhara region was fairly high as per the WHO availability index range. However, the availability of oral rehydration salt was high (82.5%) and availability of vitamin A (47.5%), morphine tablet (13.3%) and artesunate rectal suppository (7.5 %) were within low and very low WHO range respectively. Budget adequacy (AOR=12.978, CI= (2.153-78.241)),periodic review of stock level ((AOR=13.426,CI=(1.958-92.04)),training on integrated pharmaceutical logistic system ((AOR=4.567,CI=(1.015-20.554)), inclusion of WHO priority under five children medicines with facility specific medicine list (AOR=12.479,CI=(2.343-66.475)),lead time for EPSA procurement (AOR=7.903,CI=(1.391-44.894)) and level of health facility (AOR=0.009,CI=(0.001-0.122)) were significantly associated with availability of WHO priority lifesaving medicines for under- five children. Conclusion: The average availability of WHO-recommended priority lifesaving medicines for under-five children was low. Budget adequacy, periodic review of stock level, training on IPLS, inclusion of WHO priority under five children medicines with facility specific medicine list, lead