This study aimed to evaluate the hygienic quality of raw buffalo's and cow's milk sold in Assiut city, Egypt; based on the presence of Bifidobacterium spp. as indicator of fecal contamination. Bifidobacteria species forms one of the most important groups of flora in the intestine of both human and animals. Speciesisolated in humans are different from those isolated in animals. It should therefore be possible to determine contamination origin (human or animal). Seventy samples of raw buffalo's and cow's milk (35 samples from each) were collected randomly from; some dairy farms, individual cases of dairy buffaloes and cows and dairy shops in Assiut city, all samples were examined for the presence of Bifidobacteria spp. Each sample was firstly inoculated in MRS & BHIMup, then two different culture media (CMup & Bifidobacterium media (BFM)) were used for isolation and identification of Bifidobacterium. Bifidobacterium spp. was identified in 65.71 % (23samples) and 51.42% (18 samples) of raw buffalo's and cow's milk, respectively. Isolates were identified and differentiated and the findings revealed that raw cow's milk harboured          B.  dentium in 61.11% , B. suis in 27.77% and B. bifidum in only 2 samples (11, 11 %) of examined samples. B. dentium, B. suis and B. bifidumwere found contaminating 47.82, 39.13 and 13.04 % of examined raw buffalo's milk samples. Presence of B. bifidum revealed contamination of raw cow's and buffalo's milk with human stool (adult and infants); however isolates of B. suis indicated the contamination with feces of piglets. Also the detection of B. dentium in examined samples showed that there is contamination with human discharges coming from mouth suffering dental caries; human abscesses, vaginal discharges and feces. These organisms considered potentially pathogenic and have hazards effect on human health.