A flexible tube for an endoscope has an elongated tubular core body, and an outer cover which is provided over the core body. The outer cover is composed of an inner layer, an outer layer and at least one intermediate layer. In this flexible tube, any one of the layers is different from one of the other layers in its property. Further, at least one of the layers has a thickness-varying region where the thickness of the layer varies in its longitudinal direction. In addition, the inner layer of the outer cover has projections which are integrally formed on the inner layer so that the projections project into holes and/or the recesses formed on the core body. This structure makes it possible to produce a flexible tube for an endoscope that has high durability, high flexibility and high chemical resistance as well as excellent operationability.