This study applied Wiki technology and peer review to an English as a foreign language writing class. The objective was to investigate whether this system, as a collaborative platform, would improve students' writing skills. The study gauged students' perceptions about integrating a Wiki writing course and peer feedback. The participants were 32 sophomore students in an English department at a college in Taiwan. The study used a socio-cultural theoretical framework to explore students' perceptions of the effectiveness of Wiki-based writing projects and experiences of social interaction in the process of writing, based on self-reported reflections about the project, observations of student learning, interviews and surveys. Findings revealed that most students explicitly stated that they felt positive about their ability to apply Wiki and peer feedback to writing instruction. Meaningful social interaction appears to play a significant role with regard to students' perceived benefits of this collaborative writing process. Students nevertheless encountered both functional and psychological obstacles to using the new tools, indicating the need to alter their traditional learning practices to embrace new, technology-enhanced learning systems. (Contains 1 table and 2 figures.)