Composite polyester films with barrier properties

The present invention relates to polyester-based filmscomposites of having good propriétésbarrière vis-à-vis gases. Specifically, elleconcerne a stretched composite film biaxially, based depolyester that have vis-a-vis barrier properties desgaz improved, characterized in that it comprises a filmde polyester base having from 5 .mu.m to 50 .mu.m, coated on the atleast one of its two faces by a lower thickness alcoolpolyvinylique layer or equal to 0.3 microns, said composite film exhibiting a permeability àl'oxygène measured at 23 ~ C under 50% relative humidity, less than or equal to 3 cm3 / m2 / 24h. Films compositesde the invention, in addition to transparency andmixtures barrier properties, excellent mechanical resistance auxagressions such as including wrinkling. They are also easily recyclable because deleur low overall content of polyvinyl alcohol.