A flexible surgical stapler assembly includes a staple firing head assembly and a handle actuator assembly connected to the staple firing head assembly through a flexible spine. The staple firing head assembly includes an anvil assembly defining an anvil surface which provides an array of staple forming depressions. A staple housing on the staple firing head assembly carries an array of staples to be formed. A staple pusher means on the staple firing head assembly is provided for exerting a force on the staples in the staple housing to eject the staples from the housing and form the staples against the anvil surface. The handle actuator assembly includes a housing which defines an inner cavity. A cable carrier is provided within the cavity and is freely slidable within the cavity. A length of flexible cable is connected at one of its ends to the cable carrier and at its other end to the anvil assembly of the staple firing head assembly. A trigger mechanism consisting of a lever is provided on the housing operatively connected to the cable carrier for moving the cable carrier and thereby concomitantly forcing the staples out of the staple housing to form the staples against the anvil surface.