Working with in service science/mathematics teachers at the Aga Khan University Institute of Educational Development, Karachi, Pakistan we find that even though the teachers take aboard innovative ideas, they find it challenging to implement the newly acquired ideas primarily because of their inadequate subject matter knowledge. In this paper we will describe and discuss select case studies from Pakistan to provide evidence regarding this issue and support it with literature from other parts of the world. We will finally share some implications and possible alternatives to address this issue.