The fatty acid composition of "fish wurst", a fermented salami-type sausage made of pork, lard and Baltic herring fillets (Clupea harengus var. membras) was investigated. Changes in the proportions of the 35 most abundant fatty acids were examined throughout the 1-month ripening period followed by a 4-month storage period. The fat composition of the product was stable (32-35%) and retained the characteristics of the main ingredients: oleic acid (37.4%, mean of three production batches) palmitic acid (23.7%) and linoleic acid (10.7%) from lard and fish, stearic acid (11.7%) mainly from lard, and palmitoleic acid (3.0%) and long-chain (C20-C24), polyunsaturated fatty acids (c.a. 6%) mainly from fish. During the 4-week ripening period a statistically significant increase (P less than or equal to 0.05) was detected in the proportions of minor fatty acids only, i.e. eicosenoic acid (20:1n-9), eicosadienoic acid (20:2n-6), docosadienoic acid (22:2n-6) and docosatrieonic acid (22:3n-3). During the 4-month storage of the ripe sausage, the fatty acid composition stabilized. Only the proportion of stearic acid increased significantly during storage, from 11.7% to 12.5%.