This paper deals with the cause of the formation of ropy slime on the surface of vacuum-packed cooked meat products. Two different homofermentative lactobacilli and a Leuconostoc strain were isolated from different ropy vacuum-packed meat products. The strains were able to produce slime experimentally on vacuum-packed cooked sausages. The slime had a molecular weight in the range of 70000–30000 and contained glucose and galactose in a ratio 10:1–10:2. The formation of ropy slime also occurred on sausages without added sugars.