The authors focus on the application of adaptive end-to-end windowing as a reactive congestion control mechanism for data communications over asynchronous transfer mode (ATM) networks. In particular, an adaptive window mechanism including go-back (n) retransmission is proposed. The performance achievable by its application was evaluated by simulation under a particular network model assumption. The gain possible in terms of improvement of cell acceptance is estimated with different source traffic descriptors and network parameter values. Some comments on the interaction between the window mechanism and other congestion control mechanisms for ATM networks are given.>