The advent of web-based learning technologies allows students to connect and share their knowledge rapidly and conveniently in different forms from online discussion to digital resource sharing. However, this power of connectivity and ease of access does not necessarily mean that students who communicate and learn within an online learning environment are equipped with the participatory culture typically associated with the learning technologies they are using. This article explores the relationship between participatory culture and student knowledge sharing in an online learning environment. It is based on a larger research project looking into the integration of online learning environment in an academic program of a Cambodian tertiary institution. Data presented in this paper were collected from student focus groups and were analyzed through thematic analysis to understand student perceptions and practices of knowledge sharing within an online learning environment. Data analysis revealed three interrelated concepts: values, practices, and cultural context, which help explain the relationship between participatory culture and online knowledge sharing. Implications of the study indicated the need to make participation a more conscious practice and to openly discuss hidden cultural challenges in online knowledge sharing among students.