This research investigates the ways of implementing dual-language programs and the schools’ internal procedures of evaluating them. Previous studies have examined the effectiveness of bilingual programs (Genovesee et al. 2005; Howard et al. 2005; Krashen 2004). However, there is little still known about schools’ procedures that systematize the organizational aspect of such programs. The Mixed Methods Research (MMR) approach was applied in this study to analyze data collected through questionnaires, interviews, and case studies. The results of the study were combined and interpreted together. They bore out that the schools that have not introduced an effective internal evaluation system need institutional support in the form of practical publications / guides, referring to the organization of such programs, as well as in-house teacher and management training. There are often no forms of such training or resources available. This calls for improvement.DOI: 10.20420/rlfe.2015.0014