Wikipedia is one of the most important innovations of the Internet age and has been analysed and criticised within higher educational settings for how it is utilised by students or academics for essay assignments or research. Less work has been done on how content writing for Wikipedia may be deployed as an instructional tool and its pedagogical implications, particularly for English language learners. This case study describes an in-class editing project involving sociology and English literature undergraduates at a Korean university, and qualitatively and quantitatively examines its successes and difficulties. Findings from this experiment are relevant to future Wikipedia teaching projects with high-fluency second language (L2) as well as first language (L1) students at the postsecondary level.