The need for professional development via MOOCs (Massive Open Online Courses) has been increasing lately, especially during the pandemic crisis. This paper is a case study on MOOC adoption by professionals and seeks to understand the predictive power of a specific technology acceptance model. The proposed model was developed by extending the Unified Theory of Acceptance and Use of Technology (UTAUT). UTAUT was extended by specifying two facilitating conditions related to the nature of online learning and adding two extra moderation mechanisms. A survey that was using the ensuing framework was answered by 253 participants who were professionals attending a MOOC. The research findings show that users’ behavioral intention to attend MOOC is influenced mainly by Effort Expectancy and Facilitating conditions, where the emphasis is on Time Flexibility and Continuous Availability (i.e. the two newly introduced parameters related to the nature of online learning). Performance Expectancy and Social Influence were found to have less significant influence on MOOC usage intention. The effect of Social Perceptiveness and Group Work Effectiveness (i.e. the two newly introduced parameters) were also analyzed. Results show that Social Perceptiveness has a moderating effect on the relationship between Social Influence and Behavioral Intention to attend the MOOC, while Group Work Effectiveness has an effect on the relationship between Effort Expectancy and Behavioral Intention. The paper concludes with theoretical and practical implications touching the proposed extended technology acceptance model as well as guidelines targeting the acceptance of MOOCs for professional learning, respectively.