Massive open online course (MOOC) participants face diverse barriers that prevent them from feeling satisfied with participating in online courses. This study identified those barriers and their predictors. Using pre- and post-questionnaires, MOOC participants reported several characteristics and their barriers to satisfaction during the course. Exploratory factor analysis identified three kinds of barriers. The effects of participants' age, gender, level of self-efficacy, motivation, self-regulated learning skills and the intention to complete the course were used as predictors of those barriers to satisfaction. The barrier lack of interestingness/relevance was predicted by the self-regulation indices of self-evaluation, study-strategy and help-seeking. The barrier lack of time/bad planning was predicted by the self-regulation indices of goal setting, time management and study strategy and by the age of the respondent. The barrier lack of knowledge/technical problem was predicted by the level of self-efficacy, extrinsic motivation and the self-regulation index of time management, as well as by the behavioural intention to complete the course. Furthermore, an index averaging the extent of the barriers was predicted by the self-regulation indices of goal setting and study strategy, the level of self-efficacy and the level of extrinsic motivation. Theoretical and practical implications are discussed in order to help MOOC participants, instructors and designers to enhance learner satisfaction.