The invention relates to a method for an at least partial erasure of the memory content of a mobile station in a mobile communication system. The starting of the erasure of the mobile station memory content is arranged to be responsive to the checking of a unique equipment identity of the mobile station performed in the mobile communication network on the basis of the unique equipment identities included in an equipment register. If a network element providing mobile communication services receives from an equipment register element the information, according to which the mobile station that has contacted the mobile communication network is defined as barred in the equipment register, a message to be sent from the mobile communication network to the mobile station is formed for erasing the memory content of the mobile station. This message is transmitted from the mobile communication network to the mobile station, and the mobile station detects a need for an at least partial erasure of the memory content in response to the reception of said message.