Introduction. The article reveals a complicated language situation in the Flemish region of Belgium - a progressing extinction of Germanic dialects, which are historically spread on this territory. Each dialectal group has its unique features, and the West-Flemish and Limburgish groups might have become grounds for particular languages.Methodology and sources. The methodological base consists in a complex approach, combining the comparative-historical and contrastive methods with the method of sociolinguistic interpretation. The investigation is conducted on the language material, collected from different dialectal dictionaries of Dutch, as well as from special linguistic papers on the language situation in Flanders.Results and discussion. The article represents a multiplicity of Germanic dialects, existing on the territory of modern Flanders. A short revue is given on lexical and grammatical peculiarities of four main dialectal groups, as well as on their peculiar phonetics. A special attention is, respectively, paid to the urban dialects of Antwerp, Gent, Bruges and Hasselt. There are analyzed some interferential phenomena, caused by the contact of the investigated dialects with Romanic and Germanic environment and occurring on all language levels - from phonetic to the syntactic ones. It has been suggested, that certain specific grammar forms in Flemish dialects may be result of phonetic interference. For Marols, which originally belongs to the group of Brabant dialects, the juncture between Germanic morphosyntactic structure and Roman lexis is discussed.Conclusion. For the last 20 years the percentage of persons, speaking the Germanic dialects of Flanders, has demonstrated a catastrophic decrease. Along with that, the main features of these dialects (mostly of the Brabant ones) have gone over to an intermediate language “tussentaal”, in both lexis and grammar. This language is being formed inbetween the Germanic dialects and Dutch; the latter is represented in the Flemish region by two variants – standard ...