Abstract: A stair climbing aid comprises two slide rails, an assist member, a control mechanism and two positioning assemblies. The slide rails and the assist member are assembled to handrails at both sides of the stairs. The control mechanism is disposed on the assist member to be controlled by the user. The positioning assemblies are disposed at both sides of the assist member, each positioning assembly is provided with an engaging portion to be engaged in the respective positioning portions of the slide rail. Thereby, an anti-slide effect is produced, so as to prevent the user from falling down the stairs and to help the user move from step to step safely.