Early neonatal deaths, occurring within the first six days of life, remain a critical public health challenge. Understanding the trends and factors associated with this issue is crucial for designing effective interventions and achieving global health goals. This study aims to examine the trends in early neonatal mortality in Ethiopia and identify the key factors associated with changes in early neonatal mortality over time. This study utilized five consecutive Ethiopian Demographic and Health Survey datasets from 2000 to 2019. To investigate the trends and identify factors influencing changes in early neonatal mortality over time, conducted a trend analysis and a logit-based multivariate decomposition analysis. Data management and analyses were performed using STATA version 17/MP software. All analyses were weighted to account for sampling probabilities and non-response. Statistical significance was determined at a two-sided p-value threshold of less than 0.05. The analysis included a total of 12,260 weighted women from the 2000 survey and 5,527 weighted women from the 2019 survey. Over the study period, there was an overall downward trend in early neonatal mortality, decreasing from 34 deaths per 1000 live births in 2000 to 27 deaths per 1000 live births in 2019. The annual rate of reduction was estimated to be 1.03%. Approximately 45% of the observed decline in early neonatal mortality rate can be attributed to changes in population characteristics or endowments (E) during the study period. Factors such as the mother's age, maternal education, marital status, preceding birth interval, types of pregnancy, and the sex of the child significantly contributed to the compositional change in the early neonatal mortality rate. Over the past two decades, Ethiopia has seen a modest decline in early neonatal mortality, but this progress falls short of the Sustainable Development Goal (SDGs) targets. To achieve the SDGs, the Ministry of Health and its partners should intensify efforts to reduce early neonatal mortality. Strategies like preventing early/late pregnancies, promoting appropriate marriage timing, and prioritizing education could help further reduce early neonatal deaths. Further research is also needed to explore the factors driving this issue.