Built in 1252 by the Livonian Order and later passed over to the Teutonic Order, the Klaipėda castle (German – Memelburg) was the northernmost castle of the Order in Prussia. For both geographical and political reasons, it was separated from the hinterlands of the Order’s state, making its survival strategy here specific. This article analyses the zooarchaeological material found during the 1997-1999 archaeological excavations and dated to the 14th-17th centuries. The analysis of the historical data and zooarchaeological material showed that in the 14th-17th centuries, the inhabitants of the Klaipėda castle (the Order’s brothers, their servants, the outwork’s artisans, and the townspeople who hid in the outwork) reared and slaughtered domesticated animals, hunted large game and consumed its meat, processed cheese, ground grain, drank mead and ale. The bulk of the meat consisted of beef, mutton, and pork, as well as goats’ meat starting 1434. An examination of the species and number of bones of domestic and wild animals in Klaipėda’s castle shows that in all of the Klaipėda castle time periods analysed, differences were found between the historical source information and the zooarchaeological collection. Domestic animal bones dominated in the latter, especially that of ruminants (cattle, sheep, goats); pigs comprised the second group according to quantity. The growing quantity of small ruminants (sheep, goats) starting 1434 also is reflected in the zooarchaeological material; from the 16th to 17th centuries, the number of bones of these animals doubled. The amount of riding horses markedly grows in the inventory books starting the middle of the 15th century, and this also is confirmed by zooarchaeological material. When comparing the results of the zooarchaeological material’s analysis with the known 14th-16th century inventories of Klaipėda’s castle in which there are data regarding the domestic animals (cattle, sheep/ goats, horses, pigs) reared for the castle’s needs and the food eaten by the castle’s inhabitants, changes are observed in the faunal species and amounts of the zooarchaeological material that post-date 1521, when 31.25% consists of pig (Sus suis) bones, while the number of species and bone counts of large wild animals (aurochs/ European bison, elk, red deer) and fur-bearing animals (beaver, bear) grows significantly (from 5.5% to 22.92%). Various kinds of fish caught in the sea near Klaipėda and in the Curonian Lagoon held an important place in the diet of the castle’s garrison. Fowl comprised only a small part of the food.