The application of Computer Assisted Language Learning (CALL) in language courses is becoming increasingly more common. CALL is being used in a number of areas, of which vocabulary applications are receiving particular attention. This paper looks at the development of a computer-based online review system (the online vocabulary quiz) intended to assist learners with their vocabulary studies, and its application in an English for Academic Purposes (EAP) course at a university in western Japan. The study considers students' use of the online quiz, its effect on vocabulary acquisition, and students' attitudes towards the quiz. Based on preliminary findings, consideration is given to how the online quiz can be improved to better assist learners with their language needs.