Many researchers speculated that Massively Multiplayer Online Role-Playing Games (MMORPGs) could create a problem-based learning environment for students to learn teamwork skills. In this study, a highly interactive MMORPG, World of War craft (WoW) was adopted and one-group pretest posttest experiment was designed to answer two questions: (a) Do studentsi¦ teamwork skills enhance through team playing in WoW? (b) Do training outcomes vary by the roles that students play in the game? (c) Are training outcomes related to the degree of the flow experience the students have? Unfortunately, the experimental results did not support that WoW is effective in training teamwork skills.