This paper presents a mobile-computing tool that helps leading expertise knowledge of childhood oncology to many places over the country. The tool is composed of independent applications that run in different platforms and yet communicate. A system for following patients' treatment on-site was implemented for handhelds, PDA type. With this system, the tool acquires the mobility needed to make distance training in Brazil easier. Information about the patients is registered in the handheld device and then transferred to a consolidated database in the Internet, through a double-way synchronization process. A client application for personal computers integrates this project, surpassing PDAs limitations, regarding certain data entries and report printing. The server, which provides access to the corporative database, was built on Microsoft's DCOM distributed-objects? system. The database is supplied with information obtained from patients, physicians and the group coordinator, with the purpose of building a solid knowledge base on pediatric oncology.