In a cassette for dispensing flexible tubing a cassette body includes a central tubular portion defining an aperture extending therethrough. An outer wall surrounds the central tubular portion and a cassette bottom extends between and connects the outer wall and the central tubular portion. The outer wall, the cassette bottom and the central tubular portion cooperate to define an interior area that surrounds the central tubular portion. A length of flexible tubing is positioned in the interior area. The cassette bottom includes first registration features and a cover is coupled to the body and at least partially overlies the interior area, the cover defining second registration features matingly engageable with the first registration features so that cassettes can be stacked one-on-top-of-the-other with the cooperation of the first and second registration features preventing successively stacked cassettes from shifting relative to one another.