Abstract: A gearshift stick lock for an automobile having a transmission case includes a lock body, a shackle having two legs engageable with the lock body, a sleeve for wholly fitting over a gearshift stick of the automobile and extending downwardly into the transmission case, the sleeve including two threaded holes and two rings fixed to the sleeve, each of the two rings having a hole aligned with a corresponding one of the threaded holes, two screws each extending through a corresponding one of the threaded holes to bear against the gearshift stick of the automobile thereby fixedly mounting the sleeve thereon, and the legs of the shackle being engaged through the rings respectively and engaged with the lock body so as to lock the gearshift stick in place.