Biodegradable, liquid impervious multilayer film compositions are disclosed. In particular, the films comprise composite structures derived from multilayer combinations of biodegradable polymers. The biodegradable polymers are selected from the categories of moisture sensitive polymers, thermally sensitive polymers, mechanically limited polymers, polymers not easily processed into films, hydrolytically cleavable polymers, and degradable elastomers. Optionally, the multilayer films may further comprise additional adhesive tie layers. The biodegradable polymers are combined in various ways to overcome the deficiencies of the individual components, yet at the same time impart specific performance properties to the film. The multilayer film compositions are suitable for use as backsheets in disposable absorbent products including diapers, adult incontinent pads, sanitary napkins, pantiliners, and the like.