Despite the significant research interest in teachers’ innovative activities, the role of work experience and professional development (PD) as predictors of science teachers’ innovative work behaviour has rarely been studied. By using the TIMSS 2015 data of three countries with different levels of student achievements in science (Japan, Lithuania and South Africa), this article focuses on revealing how PD content, duration and teaching experience predict science teachers’ two collaborative innovative activities: working together to try out new ideas and sharing new ideas. According to Rogers’ diffusion theory, these two activities correspond to the fourth and fifth stages of innovation: implementation and sharing. The results of an ordinal regression analysis revealed that PD duration could not predict the collaborative innovative activity of science teachers and that teaching experience was a significant predictor of collaborative innovative activity only among Japanese teachers. The study showed that in Lithuanian and South African samples, PD focusing on pedagogical content knowledge, such as science curriculum, students’ critical thinking and enquiry skills and addressing individual students’ needs, positively predicted teachers’ innovative activities. The study invites future research and discussion about the role of PD duration in the collaborative innovative activity of science teachers.