Much of the research in parallel discrete-event simulation (PDES) has resulted in new experimental simulation languages or toolkits. Meanwhile, the simulation community continues to use existing (serial) commercial tools which are reportedly more powerful and flexible from a modeler's point of view. A possible way to increase the impact of PDES in the simulation community is to make existing simulation packages execute in parallel. Towards this end, we present a parallelization of the GPSS simulation language. We implement parallel GPSS as a GPSS-to-C++ translator and execute the transformed code with the help of the ParaSol parallel simulation system. The mapping from GPSS to ParaSol is simple because, unlike other parallel simulation systems, ParaSol is transaction oriented. On the other hand, because GPSS was not designed with parallelism in mind, there are GPSS constructs that can behave poorly in a parallel environment. We present details on the mapping, some of the challeng...