Water-assisted injection molding (WAIM) is a recent and promising technique to produce hollow or partially hollow parts. A shorter cycle time in combination with a lower material and process cost are the main advantages. The extra water-related process parameters, the properties of the applied material and the chosen hardware configuration (tooling, mold design,…) require however extra lead-time and/or experience with the process. Simulation tools offer the possibility to design the process in order to deduce a suitable process and material combination and/or to predict product quality. This study validates simulation results with the aid of experimental data for different material parameters and melt temperatures. It was found that simulation results show the same influence of the zero-shear viscosity and melt temperature on the residual wall thickness (RWT) as the experimental data and this within a reasonable deviation.