While debate has been raging about intellectual property rights and presumption of guilt when using anti-plagiarism software in academia, less attention has been focused on its pedagogical benefits. These benefits will be illustrated in this paper based on the use of Turnitin, for pedagogical purposes in an English-medium context in Japan. The purpose of using the software was to teach students about the issue of plagiarism and ways to detect and avoid it in their own writing. This was done to prepare the students to move into an English-medium programme and/or study abroad in English-language contexts. Thus, the use of this tool combined a very practical goal with a strong focus on learner autonomy rather than assessment. The paper will provide an overview of the different steps teachers, students and tutors took to maximize use of the various functions available in the software to analyse writing, provide feedback, and improve writing. Based on a two-semester trial period, administrative concerns and practical issues will be discussed as well as feedback from students, faculty and tutors about the effectiveness, user-friendliness and relative contribution of the software to the overall learning process.