''Urutan'' is a Balinese traditional fermented sausage, which is made of lean pork and fat mixed with spices, sugar, and salt. The mixture is stuffed into cleaned pig intestine and fermented under uncontrolled condition during sun drying for 5 days. The investigation showed that lactic acid bacteria (LAB) were the dominating bacteria during ''urutan'' fermentation. Among the 71 isolates obtained, lactobacilli dominated by 77.5% and the other 22.5% were pediococci. Based on physiological characteristics, the isolates were classified into 13 groups: nine belonged to the lactobacilli and the other four were pediococci. One isolate representing each group was chosen randomly, and then was identified by 16S rDNA sequence comparison. Phylogenetic relationship positioned three groups to Lactobacillus plantarum and four groups were closely related to L. farciminis. Two groups were identified as obligate heterofermentative lactobacilli: one was L. fermentum and the other was distantly related to L. hilgardii. Two groups belonging to the pediococci were strains of Pediococcus acidilactici and the other two were closely related to P. pentosaceus. A dramatic succession occurred during fermentation of ''urutan''. Three species mainly dominated the process wherein the initial growth was started by L. plantarum then followed by the growth of P. acidilactici, and finally, L. farciminis was found to be predominant at the last stage of fermentation.