A bed step device is provided for assisting a human or pet in climbing into and/or out of a bed. The device includes a base, at least one step attached to the base, and a retention member attached to the base. The retention member is configured to be disposed and retained between opposed surfaces of a bed, typically either the opposed surfaces of a mattress and a box spring or those of a box spring and a bed frame. The disposition of the retention member between the opposed surfaces results in a retention force, typically a friction force, to resist sliding movement of the device across a floor surface on which the device is supported. The retention member may be a rigid panel or a flexible sheet. The base and step or steps may comprise a folding staircase linkage or a rigid, unitary housing including a storage compartment.
