The invention relates to a method of controlling access to multicast IP flows. Following connection to a collection equipment by a user terminal, the method consists in: transmitting an access authorization request message from said collection equipment to an access control server; and, subsequently, upon successful verification of the user access right, transmitting an access authorization acceptance message comprising at least one multicast filter from the server to the collection equipment or, in the absence of a successful verification, transmitting an access refusal message from the server to the collection equipment in order to inhibit the connection of the user terminal. The invention is suitable for multicast broadcasting over an IP, Internet and/or corporate network.