Abstract-Many surgical procedures are now performed using the techniques of minimally invasive surgery (MIS), in which unnecessary trauma is limited by reducing the size of incisions to less than about 1 cm or by using catheters or endoscopes threaded through vessels, the gastrointestinal tract, or other tubular structures. Micromechatronic technologies have great potential to allow access to regions now inaccessible, or to enhance the surgeon's abilities in applications where current minimally invasive techniques do not permit the full range of human dexterity and perception. Key needs and applications in MIS are identified, and relevant technologies, methods, and systems issues in mechatronics are discussed. The authors' millirobotic system for MIS of the abdomen is used as an example.