Inquiry project-based learning (inquiry PjBL) has been regarded as an innovative educational approach among local primary schools in Hong Kong, replacing gradually the more traditional didactic teaching approach. Many studies have been conducted to investigate the effectiveness of inquiry PjBL in equipping students with skills needed by the 21st century. However, the lack of an effective delivery method hinders its widespread implementation. This study examined the suitability of using wiki, a form of Web 2.0 technologies, as a platform for the implementation of inquiry PjBL among Primary Five students in Hong Kong. Four schools were recruited and students (n=420) were given an inquiry group project to work on, using Google Sites as an online collaborative platform. The outcomes were evaluated using an online survey designed to assess the effectiveness of wiki in four domains: learning/pedagogy, motivation, group interaction, and technology. Focused group interviews were also conducted to obtain students’ insights regarding the learning experiences. The study found that the use of a wiki in supporting inquiry PjBL was perceived positively by students. Students found the learning experience enjoyable and the various functionality of the wiki enhanced their acquisition of knowledge and skills. Findings of this study may help provide practical suggestions to education practitioners to incorporate wiki into inquiry PjBL and help demonstrate the potential of wiki in facilitating the development of knowledge and skills among students.