The effects of food grade fructooligosaccharide (FOS), isomaltooligosaccharide (MOS), galactooligosaccharide (GOS), and inulin on the growth of five strains of bifidobacteria in fermented milk were investigated. Their effect on culture viability during refrigerated storage was also determined. FOS showed the highest growth-promoting activity for all bifidobacteria except for Bifidobacterium bifidum. Growth rates of B. adolescentis, B. breve, and B. infantis were stimulated by oligosaccharides and inulin, whereas B. longum growth was stimulated by the oligosaccharides but not inulin. In contrast, growth of B. bifidum was enhanced only by inulin. Both acetic and lactic acid production by Bifidobacterium spp. was also enhanced in the presence of 5.0% oligosaccharides. The viability of bifidobacteria cultured with oligosaccharides and inulin, particularly with FOS, was significantly higher than control cultures after 4 weeks of refrigerated storage. The utilization of oligosaccharides is likely to enhance the growth rate, activity, and viability of bifidobacteria.