Old English has traditionally been considered a period of linguistic homogeneity, since most available recorded texts are generally written in the West Saxon dialect. There are, however, isolated texts which have been ascribed to other varieties, in particular Northumbrian and Mercian. In fact, recent research on syntactic dialectology in early English (Kroch & Taylor 1997; Ogura 1999; Hogg 2004, 2006a; Ingham 2006) shows that linguistic variation has been present in the English language from the earliest times. This study reassesses the existence of variation in the syntax of texts belonging to different dialectal varieties in Old English, in particular in relative constructions. Based on an analysis of relative clauses in three versions of the Gospels from late Old English, representing West Saxon, Northumbrian and Mercian dialects, we will observe differences in the texts, regarding both the paradigm of relativizers and the position adopted by the relative clause within the main clause. I relate these differences to the existence of linguistic differences in northern and southern dialects.