Replay of partially executed instruction blocks in a processor-based system employing a block-atomic execution model is disclosed. In one aspect, a partial replay controller is provided in a processor(s) of a central processing unit (CPU). If an instruction is detected in the instruction block associated with a potential architectural state modification, or an exception occurs during execution of instructions, the instruction block is re-executed. During re-execution of the instruction block, the partial replay controller is configured to record produced results from load/store instructions. Thus, if an exception occurs during re-execution of the instruction block, previously recorded produced results for the executed load/store instructions before the exception occurred are replayed during re-execution of the instruction block after the exception is resolved. Thus, execution of instructions leading up to side-effect operations in the instruction block can be deterministically repeated with previously produced results, without repeating the side-effects.