This paper focuses on science teaching learning practices in a culturally diverse classroom of a Nepalese public secondary level science teacher who was purposefully selected. I focus on how science teaching in this science teacher's classroom is interactive, creative, collaborative and inclusive. Additionally, I explain how the school environment can create and extend multicultural science knowledge. A 50-min in-depth interview was conducted and transcribed, as well as observations of his classroom activities of science teaching which were noted in a diary. Transcribed interviews and classroom observation notes were translated into English and coded by me. All data were analyzed indicating that the secondary science teacher's efforts were not found to be culturally relevant as his efforts were affected by pedagogical, environmental and institutional problems. A heavy emphasis on the national science curriculum is destroying teacher's teaching style in a culturally diverse classroom. This article calls for the participation of other school science teachers, other group teachers, women participation and the importance of inclusion of different cultural students' voices in science teaching.