A field assemblable panel door comprises a pair of metallic stiles each having an outer wall, a pair of side walls extending perpendicularly thereto and an engagement element on the inner surface of the outer wall which provides a bore. The side walls provide a first inwardly opening panel receiving channel therebetween, and a pair of flanges on one side wall provide a second panel receiving channel. A pair of metallic rails each have inner and outer side walls, and a base wall extends between the inner ends of the side walls to provide an outwardly opening channel, and the base wall provides a second inwardly opening channel. Corner connectors join the ends of the stiles and rails to form a rectangular frame. The connectors have an outer end wall overlying the ends of the rails and a body portion extending in the outwardly opening channel. A fastener seated in the corner connector engages in the bore of the engagement element in the adjacent stile, and a panel is seated in the opposed inwardly opening channels of the stiles and in the inwardly opening channel of at least one of the rails.