Verb-Third (V3) constructions, i.e. root clauses displaying more than one element in their prefield, have been attested throughout the history of German. In this paper, I discuss some methodological issues related to the investigation of this structure in Early Old High German (EOHG, eighth to ninth century). In this language stage, the linear syntax of matrix clauses is very unstable—mainly due to the not-yet complete systematization of the V2/verb-final distinction and to the considerable amount of extraposition in main clauses—which makes the detection of this construction in the available texts particularly challenging. Moreover, little substantial and reliable prose data are extant for this period. In order to get a realistic picture of the distribution of the phenomenon at stake in EOHG, it is therefore necessary to evaluate the data by means of diagnostic tests for verb movement and only consider those cases in which the verb is unambiguously located in C and the preverbal area hosts multiple (head or non-head) elements. I will show that: (1) some of the patterns that are usually assumed to be good candidates for the category of V3 in the relevant literature are never attested in the diagnostic dataset; (2) a typology consisting of five non-correlative and three correlative diagnostic V3 constructions can be identified on the basis of an approach based on replicable methods; (3) some of these patterns display historical continuity; (4) non-prose texts are inadequate for syntactic investigations.