A message display system for a programmable controller having a function for displaying a message in different languages and an improved program processing efficiency. A message storing means for a plurality of languages includes a plurality of storing areas (1a-1c) for storing messages in the different languages. In the respective languages storing areas (1a-1c), messages having the same meaning in the different languages are stored in addresses having a sequence corresponding to one another. When a power is supplied to the PC, a message transfer means (3) transfers a message of a single language previously designated by a parameter (2) from the message storing means (1) for a plurality of languages to a message storing means (4) for a single language. Then, a message selection means (5) designates a message desired to be displayed on a display screen when the PC is in operation by an address determined to correspond to the meaning of each message, and a message display means (6) fetches the message at the designated address from the message storing means (4) for a single language and displays the same on the display screen of a display unit (7).