This research was conducted to examine factors affecting pre-service mathematics teachers' intentions to integrate Web 2.0 tools in their future teaching of mathematics. Thirty preservice teachers who registered for the elective course within the department comprised the study group for the research. At the beginning, middle and end of the two-credit course, three semistructured interviews, reflective journals and field notes were used to collect the qualitative data. The decomposed theory of planned behaviour was used to analyse the collected data. The results of this study showed that attitudes, subjective norms and perceived behavioural control explicitly influence pre-service mathematics teachers' intentions regarding Web 2.0 technology integration. In particular, pre-service teachers expressed their inclination to use Web 2.0 applications in their professional lives so as to develop student learning, communication, and share teaching materials. Although future mathematics teachers plan to apply Web 2.0 technologies in mathematics education because of pedagogical outcomes, they held the belief that successful integration of Web 2.0 is contingent upon the meaningful integration of these technologies with mathematics topics being taught and learning outcomes. This study presents some recommendations for educators who will prepare pre-service mathematics teachers to integrate Web 2.0 technologies within the teacher education program.