A plate heat exchanger includes a heat exchanger block having a plurality of heat exchange passages. On the heat exchanger block, a header is mounted that extends over at least one part of one side of the heat exchanger block and establishes a flow connection between the heat exchange passages. The plate heat exchanger is provided with a fluid connection, which is formed by the header-side end of a pipeline. The fluid connection is essentially perpendicular to the side of the heat exchanger block over which the header extends. Within the pipeline directly in front of the header, there is a flow guide.