Purpose: The research mainly aimed to identify the effect of mathematics courses performed with Web 2.0 tools on secondary school students’ mathematical achievements and attitudes towards mathematics and to examine teacher-student views on the process.Design/Methodology/Approach: The research was designed according to the mixed-method research approach. First, how mathematics courses performed with Web 2.0 tools (Plickers, Kahoot, and Edmodo) affected fifth- and eighth-grade students’ mathematical academic achievements and attitudes towards mathematics was examined, thereafter semi-structured interviews were conducted with the teacher and student views were collected using a written view form. The participants of the study is a mathematics teacher working in a secondary school located in the center of a city in Turkey and 133 students of this teacher.Findings: Consequently, while mathematics courses using Web 2.0 tools were found to have a positive effect on fifth-grade students’ relevant achievements and attitudes, eighth-grades’ achievements and attitudes did not differ. Moreover it has been determined that teacher and students have generally positive opinions about the process.Highlights: Future studies can investigate the effectiveness of different Web 2.0 tools in other courses in the long run. In addition, different variables such as attitude towards technology and digital literacy can be investigated. Web 2.0 tools can be introduced to teachers, and preservice teachers, and training can be provided to them.