The Magyarization of Romanian toponymy in historical Transylvania was achieved in three different ways: 1) adapting the onomastic material to the Hungarian orthographic and phonetic system; 2) translating the toponymic items; 3) adopting the specific Hungarian morphosyntactic rules. The Magyarization of microtoponymy did not have repercussions on the morphosyntactic and lexical levels; the adoption of Hungarian orthography ensured only the formal assimilation of the toponyms. The Hungarian orthographic principles and norms, used inconsistently, reflect numerous oscillating contexts in which the sounds ă, î, u have as graphic correspondents both labial and non-labial vowels. The Magyarization of Romanian toponymy in historical Transylvania did not obscure specific dialectal features, which highlight important information on the age and strata of populations and the relationships among them