Abstract : The interferometric gravitational wave detector Virgo is currently completing its commissioning phase and it is close to start scientific observations. Among the signals to be searched for, those emitted by coalescing binary systems are particularly promising and require a considerable computational effort to optimally search the parameter space. The Virgo collaboration has decided to implement an on-line analysis strategy capable of processing the interferometer data in-time. In this communication we present a component of the analysis pipeline, a parallel computing system based on the Message Passing Interface (MPI). We describe its capabilities, underlining its strength and flexibility, and we illustrate its relation with the other components of the pipeline. The on-line analysis chain, including the presented parallel system, has been run for the first time successfully during the Virgo commissioning run C5 in December 2nd to December 6th 2004.