In the last 20 years, Early School Leaving (ESL) in Portugal has registered a significant decrease. In order to understand the reasons for this trend towards improvement, this paper conducts an analysis of anti-ESL measures implemented in diverse educational institutions. The main objective is to understand how mainstream and alternative education can learn from each other in terms of increasing school engagement and reducing ESL. The analysis is guided by the intention to go beyond individual-oriented views of ESL and focus on wider institutional and structural issues. To achieve an in-depth understanding of these measures, interviews took place with several educational stakeholders (principals, teachers and students), and focus group discussions were conducted with students and teachers. The findings suggest that, in both mainstream and alternative educational institutions, measures to combat ESL tend to be designed and implemented in a top-down way, rather than built on the basis of young people's lived experiences and needs. However, differences were also identified, suggesting that alternative models of education seem to be rooted in a more comprehensive view of ESL, and to better adapt to the challenges that young people experience in their daily lives. Consequently, mainstream education could follow the example of alternative institutions, and develop more comprehensive anti-ESL measures, which do not focus solely on students' presumed "deficits", but seek to tackle wider systemic inadequacies. In terms of policy recommendations, the findings suggest that both mainstream and alternative education could benefit from greater exchange between institutions of inspirational policies and practices.