Abstract: A tube fitting for joining resinous plastic tubing comprises a fitting body having an opening with a conically shaped camming mouth. A tube extends into the opening. A first ferrule is slidably received on the tube and has an exterior surface which faces the camming mouth. A second ferrule is also slidably received on the tube at a location outwardly of the opening and the first ferrule. The second ferrule has a nose portion which engages the first ferrule adjacent the tube and is snap fitted within a recess formed circumferentially of the tube prior to association of the tube with the fitting. The nose portion of the second ferrule is engaged in the recess in axial driving engagement with the tube prior to make-up of said fitting. A nut member is threadedly engaged with the body for driving the first and second ferrules into the camming mouth during fitting make-up.