An adjustable fastener for a urinary catheter bag includes a slide bar, a movable jaw attached to the slide bar, a grip assembly having a passageway that is adapted to accommodate the slide bar, a fixed jaw affixed to the grip assembly, a biasing assembly attached to the grip assembly and slide bar in such a manner so as to apply a prescribed biasing pressure between the jaws to temporarily adhere them to a structural member in the vicinity of a patient who is using the catheter bag, and a hook that is pivotably attached to an end of the slide bar and configured to set the angular orientation of the hook so that the secure hanging of the catheter bag from the fastener is promoted.