Synchronization of listen before talk (LBT) back-off for synchronous access in unlicensed spectrum is disclosed. For nodes of a coordinated group of nodes, when one or more such nodes detects a failed LBT attempt, it pauses the contention widow countdown at the current counter value. According to such aspects, a procedure may be provided that specifies when such nodes can restart the contention window countdown using the current counter value or when the nodes can redraw the pseudo-random number for the contention window countdown in order to synchronize the contention window counters.