A thin film wound dressing is disclosed in which a thin, transparent, vapor-transmitting elastomeric film is coated along its underside with a suitable pressure-sensitive adhesive for securing the dressing to a patient's skin. Prior to use, the adhesive layer is protected by a removable release liner. The opposite (upper) surface of the film has a foraminous backing layer of flexible and stretchable material secured (preferably removably) thereto. The stretchable backing layer has a multiplicity of wide openings or foramina separated from each other by foam strip portions, and at least some of the strip portions preferably terminate in free ends along a peripheral edge of the film.