The Alive & Thrive (A&T) initiative aimed to improve infant and young child feeding (IYCF) practices in Ethiopia through large-scale implementation of social and behavior change communication interventions in four regions of Ethiopia. The study assessed the effects of the interventions on IYCF practices and anthropometry over time in two regions–Southern Nations, Nationalities and Peoples Region and Tigray. The intervention included IPC through counseling at the health post or during routine home visits, community mobilization activities, and a mass media campaign mainly through the radio. During the intervention period, the A&T model reached large scale with an estimated 1.5 million mothers of children under two years exposed to IPC across 295 intervention woredas (districts). An estimated 960,000 women heard the A&T radio spots, for an estimated total of 2 million mothers of children under two years reached by either IPC or mass media. Despite significant increases in the IYCF indicators, several CF practices remain very poor including minimum dietary diversity, minimum acceptable diet, and consumption of iron-rich foods. Given that household food insecurity may constrain adoption of some recommended child feeding practices, the large remaining gaps in CF practices need to be improved and sustained in this population by addressing food insecurity and other constraints in addition to implementing effective SBCC strategies. With the persistent food security challenges in the country, the important role of household food security and enabling conditions for adoption of recommended practices need to be considered in Ethiopia.