The Mary Rose sunk off Pokmouth (England) in 1545. After initial attempts to salvage her, the site remained almost undisturbed until 1965. In 1978 a decision was made to completely excavate, raise, and preserve the ship. At the time that conservation work began on individual objects, there was a backlog of 3000 organic artifacts. The passive holding procedures used for this material caused problems for much of it, so a program was established to treat all organic matter within one year of excavation. The conservation treatment devised is described. (See also AATA 21-410)