The integration of web-based discussion platforms in education is increasingly recognized for its potential to enhance pedagogical practices. This study examined the impact of web-based discussion tools on teachers' pedagogical practices in teaching organic chemistry in selected Rwandan secondary schools. The study adopted sequential explanatory research design. A total of 351 participants including 229 senior two (grade 8), 114 senior five (grade 11), and 8 chemistry teachers from two districts were randomly selected to participate in the study. Quantitative data were collected using the Reformed Teaching Observation Protocol (RTOP) and Lesson Plan Analysis Protocol (LPAP), while qualitative data were obtained from focus group discussions. The collected quantitative data were analysed by using descriptive statistics and inferential statistics (Multivariate analysis of Variance, MANOVA) while qualitative data were analysed by using thematic analysis. RTOP results showed significant improvements in terms of teachers' pedagogical practices, particularly in lesson design, content delivery, and classroom culture with an increase of 53.75 to 81.5%, 58.25 to 76.17%, and 54.63 to 87.3%, respectively. LPAP results also indicated better lesson planning post-intervention. MANOVA results revealed statistically significant differences between control and experimental groups (Wilks' Lambda = 0.257, F (1,35) = 11.614, p < 0.001), favouring the experimental group. Significant effects were also found based on teacher age (p < 0.001) and experience (p < 0.05) with regard to younger (18-25 years) and less experienced teachers (1-3 years). However, the study did not found statistical significant differences with regard to gender, location, and school ownership. Qualitative findings emphasized improved student engagement and reflective learning. Thus, the use of a web-based discussion approach led to enhanced student-centered instructional strategies and more interactive classroom environments. The study recommends strengthening digital literacy, infrastructure, professional development, and assessment integration.