Abstract: A device for packaging and dispensing viscous and/or pasty products comprising a sachet (9) for protecting the product until it is in its final place of use, where it performs the function of a dispenser. The sachet exhibits the shape of a “W”, so as to obtain a flat bottom, which is provided with cuts (7) acting as a valve, thereby allowing the product to be dispensed. A removable protective seal (11) covers these valves (7). The device for packaging and dispensing comprises a reusable enclosure (5) of cylindrical form made from a plastics material comprising two ends, one receiving a piston (3) and the other the sachet. The sachet with a flat bottom closes off the end of the enclosure. The piston is inserted at the other end of the enclosure, so as to compress the sachet and expel the contents thereof through its valves (7) that are cut into the bottom of the sachet.