Surface characterization of molecules may provide useful information about their functionalities and potential interactions with other molecules. Even if many algorithms and tools for the protein surface modeling were proposed, presently a suitable and efficient system that enables wide range analysis of the protein external morphology does not exists. In this paper we present a parallel workflow for the reconstruction of molecular surfaces based on a set of Grid Services. The aim is to provide scientists to get easily and quickly an accurate surface representation of the molecules made available in the Protein Data Bank. The system front end is represented by a Java application, that is responsible to manage the computation on the basis of the parameters specified by the user. Furthermore, the application permits to directly visualize the resulting molecular surface and to download it on the user machine. The modular approach we propose allows in perspective the extensibility of the system through the integration of further Grid Services, in order to perform even more complex surface analyses in the Grid environment.