The article highlights the problems related to how ancient Persian culture in the Middle Ages had a powerful influence on the formation and development of folklore of the peoples of South Dagestan. Regional, ethnic, linguistic and cultural symbiosis was formed In the Derbent region, Tabasaran and Lezgistan in the V-XVIII centuries, which led the folklore of the Tabasarans, Lezgins, Azerbaijanis, resettled here Iranian-speaking Tats, Persians and Arabs to mutual enrichment and intensive development. Domestic, cultural and commercial relations led to the fact that most residents began to freely speak the “old Turkic”, Persian, Lezgin and Tabasaran languages, which ethnic groups used in communication, trade and in everyday life. The result of the influence of Persian folk and Ashug poetry on the development of the creativity of the peoples of the region can be considered the formation of a single form of genre varieties of extra-ritual lyrics and wedding poetry in the folklore of Tabasarans, Lezghins, Agulians in the form of band-quatrains. Fairy tales of the peoples of the region were also positively influenced, they were enriched by Eastern plots, themes, ideas, colorful images, Persian toponymy and vibrant poetry of genres.