In SEAMEO-member countries, numerous forms of alternative modalities have been and are being implemented. SEAMEO INNOTECH launched a research project to document successful secondary level alternative delivery models. The aim was to consolidate best practices, study more closely how the programs were executed given the varied contexts, and identify factors that contributed to their success. This project resulted in the documentation of four exemplary ADM programs, which shall be presented as a series of case studies. These include: i) the school-industry partnership of the Multiple Entry Exit System (MEES) of Indonesia; ii) access to secondary education of island learners in Vietnam; iii) flexible learning delivery modalities and learner-centered support system of the Open High School Program (OHSP) of the Philippines; and iv) project-based learning approach in support of a needs-based curriculum evident in the Home School Program of Thailand. Each case study discusses the various components of the program and highlights the unique and facilitative factors underlying the successful ADM initiative.