While research suggests that study abroad (SA) benefits second language (L2) oral fluency, its benefits for other domains are less clear, especially for shorterterm programs, which are becoming more common. Additionally, studies investigating the relationship between cognitive capacity and benefits of SA report inconsistent patterns. In light of these gaps, this study investigated whether a 5-week intensive language experience abroad benefits L2 lexical and grammatical development and whether development is related to learners' cognitive capacity. Twenty-six L1 English-advanced L2 Spanish participants in a SA program in Spain completed pre-/post-SA grammaticality judgment (GJT) and lexical decision tasks (LDT). On the GJT, results showed higher accuracy and decreasing reaction times (RTs); specifically, accuracy increased on word order and number agreement items but not on gender agreement. RTs did not decrease for any of the three targets individually. For the LDT, performance on nonwords, but not words, showed improvement while RTs for both words and nonwords decreased. Overall, these gains following short-term experience abroad were independent of variation in cognitive capacity. This study makes a unique contribution toward understanding the roles of L2 proficiency, context, and individual differences in morphosyntactic and lexical development.