Many experiments, based on the road map of the European High Power laser Energy Research facility project, were performed to study fast electron transport in compressed matter in the context of fast ignition approach to inertial confinement fusion. The generation of high intensity beams from laser–matter interaction extends the possibility to use protons as a diagnostic to image imploding targets in these experiments. The analysis of experimentally obtained proton images requires a careful analysis and accurate numerical simulations using both hydrodynamic and Monte Carlo (MC) codes. An experiment has been performed in 2008 at Rutherford Appleton Laboratory to study fast electron propagation in cylindrical imploding targets illuminated by four laser pulses. In this paper, we present new simulation results in 3-D geometry. Three-dimensional density map is generated by running the 3-D version of the MULTI code. Proton radiography images are then simulated using the MC code MCNPX.