A walker adapted for attachment to a wheelchair may be used to assist a user with walking while retaining the wheelchair in close proximity behind the user for use when the user needs to sit. The walker may be removably attached to the frame of the wheelchair for easy exchange of use from one wheelchair to another. A pivotable, removably attachable gate between two vertical rods may allow for the walker to be manipulated from a walking position to a stored position. The gate may include an extendable width to allow for use with wheelchairs of different widths. Telescopic supports may attach the walker to the wheelchair, thereby allowing the user to extend and retract the walker between the walking position and the stored position.