The present invention provides a multi-function laparoscopic surgical instrument that meets niche needs in the expanding field of Minimally Invasive Surgery (MIS). A preferred embodiment of the present invention comprises a sheath that may be inserted into a patient, wherein the sheath contains at least two interchangeable surgical instruments that may be advanced into or retracted from the patient through a single outlet in the sheath. It is intended for use in laparoscopic and thoracoscopic surgical procedures, including intra-abdominal, intra-thoracic, intra-pelvic and arthroscopic MIS procedures, and is particularly well suited to single incision laparoscopic surgery and Natural Orifice Translumenal Endoscopic Surgery (NOTES).