Professional development for teachers is often described as a journey. This paper, using the findings from a small-scale study interrogating professional development in ICT, offers the alternate metaphor of an interwoven Celtic knot to explain this phenomenon. It will show how the four key elements identified as being critical to creating the most conducive conditions for effective professional development are interdependent parts of a whole. This "whole" is here represented as an iterative loop with theory and practice as its diametric but connected opposites. The connections between these opposites encompass the four elements in a dynamic process. Like a Celtic knot, there is no defined beginning or end nor do these elements work in a straight line. This paper attempts to show the inherent dynamism and interdependence of these elements and argues for professional development for teachers which consider both theory and practice. The understandings from this dynamic model underpin the published position statement of QSITE (Queensland Society for Information Technology in Education). (Contains 4 figures.)