The invention concerns a method for transmitting a multicast stream in a data exchange network, at an access point (AP). It consists in analyzing (A) the multicast stream by data frames to detect the multicast address at the link (MUAx, x=2) of the multicast stream {MUF{T[MUA]}), substituting (B) in each frame at the multicast address (MUAx) at the link a unicast address (UNAy) of a potential receiver terminal (Ty) of the multicast stream to generate a substituted multicast frame (T[UNAy]), transmitting (C) instead of the multicast stream at least one unicast stream, a succession of substituted multicast frames to the terminal at the unicast address at the link. This allows taking advantage of the acknowledgement mechanisms of frames of the transmission of unicast stream for substituted multicast frames. The invention is applicable to transmission of multicast stream in WiFi or CPL network.