A balloon assembly including a pedestal portion having a mounting bracket for attachment to an upright support. A rod projects upwardly from the mounting bracket and carries a cup at its top with a pair of opposed slots. An inflatable portion is releasably connected to the pedestal portion and has an air-filled bladder to the bottom of which a cap is affixed. The cap is adapted for positioning within the cup and has a pair of resilient tabs extending downwardly therefrom for positioning within the slots in the cup. Each of the tabs has an outwardly projecting shoulder for releasably catching upon the cup.