A device for minimally invasive tendon sheath release is presented. The device enables a surgeon to cut (“open”) a pulley that is obstructing a nodule and keeping a tendon from sliding smoothly. The device is generally comprised of a shaft having a guide probe at a distal end and a slidable blade positioned to slide longitudinally from the proximal to the distal end of the device. The device is inserted through a small incision and the guide probe 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 sliding the blade from the proximal to the distal end of the device until the pulley is completely released or where resistance is no longer felt.