Recent years have seen the emergence of Web 2.0 in English as a Foreign Language (EFL) teaching and learning, in which students are exposed to an online space where they are not only passive recipients of the featured content but actively engaged in a dynamic interaction and construction of their knowledge and understanding. This study illuminates the nature of Web 2.0 technology integration in EFL writing and examines how the interactive and collaborative features of blogs and wikis were incorporated into an undergraduate writing course in Taiwan. This study adopted mixed research methods to explore the pre-determined dimensions and underlying factors related to and influencing learner satisfaction. A total of 37 Taiwanese EFL students were recruited. At the end of the writing course, they filled out the demographic and learner satisfaction survey online. Sixteen students and the instructor took part in the interviews. The quantitative data were collected from the survey and writing test scores, while the qualitative data were collected from retrospective interviews, online archived assignments, course-related materials, and observations. Correlation analysis was applied to identify the association between the different dimensions and factors with learner satisfaction. Descriptive statistics, interview data and writing test scores were analyzed to determine the impact of the different factors on learner satisfaction. Dimensions and factors correlated with learner satisfaction include: (1) course dimension—course effectiveness; (2) technology dimension—perceived usefulness (of wikis), perceived usefulness (of blogs), perceive ease of use (for blogs); (3) environmental dimension—learner community support, peer assessment system (for wikis); and, (4) instructor dimension—instructor feedback timeliness. No factors in the learner dimension were found to be associated with learner satisfaction. According to the instructor and students' reflections, the technology background of Taiwanese university students, and their learning needs and culture can explain the findings related to their satisfaction with the blog- and wiki-supported writing course. In light of the findings, several implications are drawn for instructional design, classroom practice and research methods in EFL writing. / text