In the last decades the conceptual and technological support for e-government initiatives have evolved from simple websites where news and links to e-government organizations and documents were posted, to complex inter-organizational systems platforms providing dynamic support for collaborative business processes (CBPs) and interoperability within e-government organizations, users and partners. Business Process Management (BPM) deals with the process lifecycle and technologies in organizations willing to drive their business based on the underlying processes they perform, to provide services or products with value for end users. Although many advances have been made in both the foundations of BPM and the technological platforms supporting the enactment of processes, e-government collaborative process present several challenges to be yet addressed.