All interventions have one aspect in common – the pursuit of positive change, ie, moving towards a particular intervention goal. In intervention both sudden changes and long-term changes are necessary – sudden changes act as an incentive to carry on with intervention as the “effect of intervention” is quickly seen, whilst longer term changes are important for maintenance and mastery of particular skills. The purpose of this article is to explore both types of change from a systems theory perspective. Bifurcation points, stabilising central attractors (SCA) and functional and structural linkages are used to explain sudden change, whilst equifinality and self-stabilisation are explained with reference to long-term change. This article concludes by pointing to specific implications for intervention when using systems theory as the framework.