This paper reports on a study exploring the in-service elementary school teachers satisfaction as far as the design and implementation of a Massive Open Online Course (MOOC), which took place during the second wave of pandemic COVID-19 and prepared in-service elementary school teachers how to teach biological concepts in Primary School with the utilization of digital educational content and Open Educational Recourses (OER). A total of 251 teachers enrolled in this MOOC of whom 142 completed the course and were asked to fill-in a questionnaire. The findings indicated that the majority of the participants were satisfied both with the specific learning experience and the participation in a learning community in which interaction, support and active participation were developed. Recommendations are made for future research.