Holding of unripe avocados for extended amounts of time in cold storage is also common as packers and distributors respond to market demand. In addition, a large proportion of the fruit marketed in the United States is foreign in origin, sometimes necessitating lengthy transit times (21–28 d) while the fruit are in an unripe state. Fruit during long distance shipment may either be pretreated with 1-MCP (SmartFreshSM) or shipped in controlled atmosphere equipped containers to prevent in-transit softening. These fruit will also benefit from ethylene ripening. Softening is known to occur in unripe avocados during cold storage (Zauberman et al., 1973 and Eaks, 1976) and acts to reduce the time needed to achieve full ripeness after the fruit are warmed. Ethylene is often used during the time of final ripening to facilitate the ripening process. The impact of ethylene on fruit that have undergone such storage is, however, incompletely understood as are the effects on quality.