This paper reports on the use of an intelligent agent framework (called CAST-ITT) for implementing a team training system. CAST (Collaborative Agents Simulating Teamwork) provides the underlying model of teamwork and agents to simulate virtual team members. CAST-ITT (Intelligent Team Trainer) uses CAST to also monitor trainees, and support performance assessment and coaching for the purposes of evaluating the performance of a trainee as a member of a team. We demonstrate that a team training system can be built that uses CAST-ITT with good performance and can be used for achieving real world training objectives.