The dire need of some schools to boost the academic performance of their students inevitably rests with their ability to attract highly qualified teachers. As such, the UK has put in place the Advanced Skills Teacher (AST) scheme, while the US has set the ball rolling in laying down standards for the certification of the master science teacher, to distil the best teachers from this pool of highly qualified science teachers. This article examines some of the practices in the teaching-learning process one would associate with those of master science teachers. It argues for the master science teacher to have a well-developed pedagogical content knowledge rather than be an expert in content knowledge. It argues for the master science teacher to be someone who has moved "from personal comprehension to preparing for the comprehension of others" (Shulman 1987 "Harv. Educ. Rev." 75 1-22).