The aim of this study was to develop a computational fluid dynamics (CFD) model to simulate the injection of liquid and foam sclerosants into a varicose vein. The CFD model results were compared with sclerosant flow in an experimental model of a straight or a branched vein. The effects of injection angle, injection velocity and tubing contents (blood, saline) on sclerosant spreading were assessed by CFD. The simulation of liquid sclerosants injection was able to provide a good representation of forward flow, but underrepresented sclerosant backflow. Due to the complex nature of computational modelling of foams, CFD modelling of foam sclerosants injection was less accurate and provided only limited information on foam spreading. CFD modelling can be used as a representation of liquid and foam sclerosant injection, but further research is required to provide a more accurate analysis.