An apparatus and method is described herein for adaptive thread scheduling in a transactional memory environment. A number of conflicts in a thread over time are tracked. And if the conflicts exceed a threshold, the thread may be delayed (adaptively scheduled) to avoid conflicts between competing threads. Moreover, a more complex version may track a number of transaction aborts within a first thread that are caused by a second thread over a period, as well as a total number of transactions executed by the first thread over the period. From the tracking, a conflict ratio is determined for the first thread with regard to the second thread. And when the first thread is to be scheduled, it may be delayed if the second thread is running and the conflict ratio is over a conflict ratio threshold.