System dynamics modelling includes a set of conceptual and numerical methods that are used to understand the structure and behaviour of complex systems, such as socio-ecological systems. A system dynamics model represents the causal relationships, feedback loops, and delays that are thought to generate the system behaviour. System dynamics is widely used for developing environmental models and decision support systems. However, little attention has been given to reflecting on modelling exercises in terms of the utility of system dynamics, its strengths and limitations, experienced during modelling and implementation challenges. These practical lessons are useful for guiding modellers on deciding when and how to use system dynamics. The purpose of this paper is to shed some light on these issues drawing on experience from six case studies. Case studies demonstrate a wide range of applications (e.g. land use, groundwater management, urban water systems), tools, modelling approaches (e.g. coupled, integrated), and computational software.