The Vietnamese dialect spoken in Ba Vì (Hà Nội) includes multiple local varieties, but these varieties have yet to be investigated as independent research objects. Using the methods of instrumental phonetics, this study aims to provide a synchronic description of the tone systems of some Ba Vi local varieties (those spoken in the communes of Phú Châu, Đồng Thái, Vật Lại), and to compare them with the tone systems of Hanoi Vietnamese and other varieties in the Xứ Đoài region (Thạch Thất, Quốc Oai, Sơn Tây). The results show that these local varieties all have a six-plus-two-tone system, each with its own distinctive and peculiar features. Furthermore, a comparison of these tone systems with that of Hanoi Vietnamese, as well as the Thạch Thất, Quốc Oai and Sơn Tây varieties shows notable differences in terms of pitch height, pitch contour, duration, and phonation type. These results initially suggest that there are truly many different local varieties of the Vietnamese language in Ba Vi, characterized by significant phonetic divergences, which should be further investigated and studied intensively.