Method and system for multicast broadcasting towards a roaming terminal according to the location thereof in relation to its site and/or original organization. Upon connection of the roaming terminal and transmission towards the site of a signalling message, it is possible to discriminate at the site an item of locating information of the roaming terminal whereby the latter receives a signalling acknowledgement message containing the locating information. When a request is made by the roaming terminal for access to group multicast broadcasting, involving a request for an address, the request is substituted or not by an extended multicast broadcast request according to the location of the connection of the roaming terminal, whereby the new address makes it possible to receive all local broadcasting at the site and/or at the original.