Learner intrinsic motivation is a critical factor that directly influences meaningful engagement, facilitates academic achievement, promotes individual learning experience, and decreases dropout rates in both online learning contexts and in various higher education settings. Intrinsic motivation is a key psychological aspect that individual learners need to have when participating in online learning activities in order to achieve their learning.Most of the research on massive open online courses (MOOCs) has been largely conducted using developed country MOOCs to examine the experiences of MOOC learners including their motivation to register for MOOCs and to participate in learning activities. However, very little empirical research using developing country MOOCs has been conducted to investigate the same phenomenon. Specifically, qualitative case study research examining learner intrinsic motivation during the MOOC learning activity in the developing country context such as Thailand has been urgently needed.This qualitative case study research is aimed at investigating learner intrinsic motivation in a massive open online course (MOOC) within the context of Thailand as a developing country through the eyes of the learners. Semi-structured interviews were used to collect data and a thematic analysis was used to analyse the data. The findings found that there were three factors of social conditions, environment conditions, and cultural conditions that influenced a perception of competence and autonomy. Social conditions include peers, course facilitators, self-motivation, colleagues, and family members. Environmental conditions include accessibility, learning activities and resources, collaboration tools, learning systems, discussion forum, and feedback. Cultural conditions include Thai learners' traits and seniority.The empirical findings of this research would be of potential contributions to theory and practice by informing MOOC stakeholders in the planning, developing and delivering of high quality of MOOC courses.Cognitive evaluation theory as a sub-theory of self-determination theory was used to examine the social, environmental and cultural conditions. These conditions played a significant role in facilitating or diminishing learner intrinsic motivation in this qualitative case study research.