There is a global interest to study lactic acid bacteria (LAB) of artisanal fermented products like yoghurt for improving or replacing current strains used in commercial starter cultures. In this work, five traditional yoghurt samples were collected from different areas of Khorasan-e-Razavi. Grouping and identification of isolates were carried out on the basis of physiological and biochemical tests (nonmolecular), as well as ARDRA technique and sequencing (molecular methods). Totally, 71 isolates including 33 Streptococcus thermophilus, 30 Lactobacillus delbrueckii (subsp. Bulgaricus and lactis), were identified as dominant strains in all yoghurt samples. Also 8 other isolates belonging to Lactobacillus helveticus, Pediococcus pentosaceus and Weissella cibaria were observed. Results of this research show the diversity of LAB population in collected samples.