Abstract: A pipelined data processing system is provided having a branch prediction mechanism which monitors instruction flow and provides a record in a prediction memory indicating whether or not a branch instruction branched when it was last executed. When a branch instruction is encountered, the corresponding prediction indication is accessed from the prediction memory using a hash-coded version of the instruction address. This accessed prediction indication is used to permit immediate sequencing to the predicted next instruction (which is already in the pipeline) if the prediction is correct. If the prediction is incorrect, sequencing to the predicted next instruction is prevented. Instead, the correct next microinstruction is accessed and executed and the corresponding prediction indication in the prediction memory is corrected.