Abstract: A system 10 for remote operation of a deadbolt lock locks or unlocks a deadbolt 22 associated with a door 14 with a remotely-operated actuator 28 that is operationally coupled to deadbolt 22. The system 10 can convert an existing manually operated deadbolt 22 into a remotely operated deadbolt by replacing an existing turnpiece associated with the manually operated deadbolt with a remotely operated actuator 28. Alternatively, the system 10 can lock door 14 of building 12 by mounting system 10 on or in either door 14 or building 12. System 10 can cooperate with other security systems in the building, including a siren 34 or a window sensor 46.