A method and device for transmitting a location registration result of a portable terminal that is adapted for connected with two or more networks includes transmitting to a first network a location registration request message for location registration, receiving a location registration rejection message including location registration rejection information from the first network when the location registration fails, and transmitting to a second network a location registration request message including the location registration rejection information. The second network can notify the portable terminal when a re-attempted connection with the first network can be performed to save on processing power for repeated re-connection attempts with the first network that will not be successful.