RPathVisio is an R package created to facilitate access to the pathway visualization program PathVisio through PathVisioRPC, the XML-RPC user interface for PathVisio. PathVisioRPC allows access to PathVisio functionality from other programming environments. PathVisioR uses this in the context of the R environment. It has a function to start a PathVisioRPC server directly from inside R, and provides easy calls that enable users to create their own pathways and to visualize experimental data on these pathways from the R environment.