The goal of this research was to examine the change in the skills, Technological Pedagogical Content Knowledge (TPACK) and self-efficacy beliefs of chemistry teachers regarding video editing and using YouTube videos in high-school chemistry lessons, as a result of a professional development program that focused on editing YouTube videos and the accompanying teaching pedagogy. Sixteen experienced chemistry teachers participated in a professional development course regarding video editing skills and the use of videos in chemistry teaching in Israel. Research tools consisted of (1) a pre-post questionnaire, (2) interviews with teachers, (3) an analysis of the videos they edited (which were part of the course assignment), and (4) follow-up interviews conducted ten months after the end of the course. It was found that teachers improved their skills and developed a unique TPACK that combines videos with chemistry teaching needs. Self-efficacy beliefs were found to be high for most of the teachers: they all trusted in their ability to integrate videos in their chemistry teaching but not all of them were confident in their video editing skills.