A portable surgical training device is provided. The trainer includes a top cover spaced apart from a base to form a simulated body cavity for locating model organs that are substantially obscured from the field of view of the user. The top cover includes a video display, fixed insertion ports and interchangeable inserts containing simulated tissue layers. The training device has open sides for demonstrating and training lateral surgical techniques including a simulated or live tissue colon attached to a support leg for simulating transanal minimally invasive surgery. A training endoscope with an adjustable focal length for use with the trainer and, in particular, with optical trocars is disclosed. The surgical trainer can be angled and is well suited for training laparoscopic surgery techniques and demonstrating surgical instruments.