This study examines the effects of subtitled similar task videos on language production by nonnative speakers (NNSs) in an online task-based language learning (TBLL) environment. Ten NNS-NNS dyads collaboratively completed four communicative tasks, using an online TBLL environment specifically designed for this study and a chat tool in WebCT-Vista. Five dyads were provided with subtitled similar task videos and the remaining five dyads were not. Language production was investigated in terms of fluency, accuracy, and complexity, including lexical and syntactic complexity. The data from the chat-scripts showed that NNSs produced more fluent and more accurate language when provided with the subtitled similar task videos than when they were not provided with them. (Contains 5 figures and 4 tables.)