A theft prevention apparatus for a leisure vehicle including a portable device, a lock device, a lock operation stopper member, a pull-out operation stopper member, a lock operation restricting actuator, a pull-out operation restricting actuator, and a controller including a memory, a receiver, and a processing unit configured to control the lock operation restricting actuator to cause a lock operation stopper member to be moved from the position where a protruded operation and a retracted operation of a lock bar are disabled to the position where the protruded operation and the retracted operation are enabled and to control the pull-out operation restricting actuator to cause a pull-out operation stopper member to be moved from the position where a pull-out operation of the mechanical key is disabled to the position where the pull-out operation of the mechanical key is enabled, when the user identification codes match.