This study investigates the relationship between extramural English and levels of English vocabulary as defined by the CEFR framework and word frequency among pupils at year 5 in a Swedish primary school. 25 pupils from two different classes participated in the study. Pupils were divided into two groups based on their usage of and exposure to English in their spare time, referred to as the high exposure and low exposure groups respectively. The results from this study show a connection between an extensive exposure to extramural English and the development of a more advanced vocabulary of English words as defined by the English Vocabulary Profile scale, in turn based on the CEFR levels A1-C2 and corpus-based word frequency derivations. One interesting aspect that came up was that while both of the groups were using almost the same level of low frequency words, the high extramural English group used more difficult, higher level words. A conclusion is that the most common extramural activity amongst these pupils, that of playing computer games, might explain this group's acquisition of higher level, more specialized vocabulary items in comparison with the other group which encountered extramural English less often.