Language aptitude and working memory are considered to be the most important cognitive variables that affect success in language learning. Our research investigated the relationship of verbal working memory, language aptitude and proficiency among 64 first-year students of a bilingual secondary school in Budapest, who participated in a year-long intensive English course. Among the components of language aptitude inductive language learning ability was found to show the highest correlations with competence in a foreign language. Verbal working memory span was moderately correlated with vocabulary, grammar skills and fluency in English. On the basis of our results, we argued that verbal working memory does not only play an important role in learning foreign language words and sequences , but also in how efficiently the learners can retrieve their acquired knowledge in these fields and how well they can divide their attention between planning the content of their message and linguistic processing. In our research we found no relationship between verbal working memory span and language aptitude, which seems to indicate that these two cognitive variables contribute separetely to the success of language learning.