A cable threader device for passing a guide cable between pedicle screws during minimally invasive spinal surgery, the device comprising a handle with a trigger mechanism, the handle mounted onto an elongated shaft having a curved free end with a detachable curved lead member retained in telescoping manner on the end of the body. The guide cable is affixed to the lead member, the instrument is inserted into a first screw tower, the trigger mechanism is activated to advance the lead member into the adjacent tower, and the lead member and guide cable are retrieved through the second tower. Alternatively, the lead member is a hollow sleeve and the guide cable is pushed through the lead member.