The present article reports on the findings of a study that explored the effect of explicit language learning strategy instruction on the development of English as a foreign language within a higher education setting in mixed language ability groups. The research results indicate that explicit language learning strategy instruction that aimed at enhancing language progress in groups of students that were heterogeneous in terms of initial language ability did not have any statistically significant effect on the development of language knowledge. These results indicate that under certain circumstances (limited course time and heterogeneous language competence levels within groups in particular) the organization of strategy training in the form of a separate module or implicit training in the use of language learning strategies seem to be more appropriate.