The design of a training program for Graduate Teaching Assistants (GTAs) at the University of Washington and its current implementation are described. Departmental training for GTAs is administered through the Center for Instructional Development and Research (CIDR). Training support provided by CIDR is based on a Train-the-Trainer model, which assumes that leaders/supervisors should play an active role in training their subordinates. A summer GTA training planning meeting for faculty GTA training coordinators and graduate student representatives demonstrates the use of the instructional lab and other tools, and facilitates small group discussions about training concerns of department members. Workshops are also conducted on a variety of topics, such as GTA orientation and instructional technology. Typical workshops that are included in TA orientation are described, and a timetable for planning GTA orientation activities is provided. Instructional materials for GTA training programs that have been developed by CIDR are also described, along with CIDR videotape facilities and services, TA training follow-up, consultation services, and CIDR research. (SW)