Embodiments of the invention relate to implementing run-time instrumentation sampling in transactional-execution mode. An aspect of the invention includes a method for implementing run-time instrumentation sampling in transactional-execution mode. The method includes determining, by a processor, that the processor is configured to execute instructions of an instruction stream in a transactional-execution mode, the instructions defining a transaction. The method also includes interlocking completion of storage operations of the instructions to prevent instruction-directed storage until completion of the transaction. The method further includes recognizing a sample point during execution of the instructions while in the transactional-execution mode. The method additionally includes run-time-instrumentation-directed storing, upon successful completion of the transaction, run-time instrumentation information obtained at the sample point.