The paper describes a novel method for the simulation of the multi-stage flashing (MSF) desalination process. The method is based on a modular simulator, CAMEL(TM), described in a series of publications by the same authors, which has been expanded by adding elemental software modules to simulate the MSF process. Originally, the code was developed with the purpose of simulating thermal power plants only, but its structure was designed and produced in such a way that enlargement of its simulation capability to include different processes would have been easy to implement. "Easy to implement" means here that this extension of the simulation capabilities does not imply any modification to the solution algorithm itself, but it is limited only to the development of the mathematical model of the new process components (i.e., the flashing stage), and to the implementation of the corresponding elemental software module. The present paper describes the results of an application of this new version of the code to the modelling of the MSF desalination process: a complete, 20-stage desalination plant is simulated, under steady- and unsteady-state operating conditions, and the results are compared with the available experimental data. The agreement is shown to be very good, and, what is more encouraging, the model calibrating parameters are not strongly case dependent. A summary of the results obtained is presented, and a forecast is made on the possible future developments of such a line of research.