Provided are a flexible tube for an endoscope, the flexible tube having a flexible tube base containing metal as a constituent material, a resin cover layer that covers an outer periphery of the flexible tube base, and a primer layer that includes a specific silane coupling agent and that is disposed between the flexible tube base and the resin cover layer, in which the resin cover layer includes at least one compound selected from the group consisting of polyamides, polyesters, polyurethanes, and polyolefins at least on a side of the resin cover layer in contact with the primer layer, an endoscopic medical device including the flexible tube for an endoscope, a method for producing the flexible tube for an endoscope, and a method for producing the endoscopic medical device.