A device and method for minimally invasive tendon sheath release. The device and method that enables a surgeon to cut (“open”) a pulley that is obstructing a nodule and keeping a tendon from sliding smoothly. A ball tipped guide probe goes through a small incision and is used to find the edge of the pulley. Once found, the probe is guided to an end of the pulley. After proper position is assured, a cutting blade is deployed by pushing and holding a blade deployment switch. This deploys the sharp end of a retractable cutting shaft beyond the sheath. The entire device is then pushed or pulled using the device handle along the pulley until the pulley is completely released or where resistance is no longer felt. In an alternate embodiment, the cutting blade is static.