A bag-making and packaging machine, in which a horizontal bag-making machine and a packaging machine are provided, including a positioning conveyor for positioning bags fed out from the horizontal bag-making machine, a feed conveyor for feeding the bags to the packaging machine, and first, second, and third transport mechanisms provided between the positioning conveyor and the feed conveyor. The first transport mechanism lifts up the bags up and change their attitude to a vertical attitude with the bag mouths oriented upward. The second transport mechanism receives the bags from the first transport mechanisms, transports them, and rotates the bags to orient bag surfaces in the feed direction of the feed conveyor. The third transport mechanisms receives the bags from the second transport mechanisms, changes their attitude to a horizontal attitude, and places them on the feed conveyor with the bag mouths oriented in the feed direction.