A storage device for removable attachment to a shopping cart includes a collapsible container having an interior storage space accessible through an upper opening; and an attachment assembly secured to the collapsible container and including at least one attachment for removably securing the collapsible container to the shopping cart. The at least one attachment can be one or more pairs of hooks of different sizes interchangeably and removably attached to the collapsible container. The attachment assembly includes an attachment bracket secured to the collapsible container that forms one or more pairs of spaced-apart predetermined attachment locations for the one or more pairs of hooks.