This study reports on how project-based language learning in which L1 Japanese EFL learners created short videos affected L2 oral proficiency. Students took short speaking tests before and after the class, and the fluency, complexity and accuracy of the pre- and posttests were measured to see which, if any, of these three aspects of proficiency would show improvement. The results indicated that participants made marginal progress in fluency, reducing their number of pauses and increasing their raw speech rate slightly, and significantly improved their syntactic complexity (p<0.001, d=1.1) and both syntactic (p=0.04, d=0.48) and pronunciation accuracy (p=0.002, d=0.75), but did not seem to make gains in lexical complexity. Overall, the results suggest that project-based learning can result in clear improvements in oral proficiency, meaning that it can be appropriately implemented in oral communication classes, but that the greatest gains are likely to be made in accuracy and syntactic complexity. However, it is still unclear whether different types of project settings will affect L2 oral proficiency in the same way.