A safety device (1) for fire-arms (11), includes actuator elements (10; 10′; 19, 20, 21, 21′, 22), suitable to engage with mechanical parts of the fire-arm (11) so as to prevent and/or permit its operation; and a control unit (2), operatively connected with the actuator elements (10; 10′; 19, 20, 21, 21′, 22), the control unit (2) including transceiving elements (3), cooperating with certification outer members brought by an authorized user (U) for exchanging signals with the same for codified remote control of the actuator elements (10; 10′; 19, 20, 21, 21′, 22). A remote control system for one or more firearms provided with the safety device is also disclosed.