The Old High German clause connector wanta (‘because’) has been variously categorized in the literature, as well as in the largest existing corpus of annotated Old High German texts (the Referenzkorpus Altdeutsch ), with respect to its selectional properties: when it introduces a causal clause, it is generally classified as a conjunction with variable (coordinating or subordinating) formal features or, in a smaller number of cases, as an adverb. This heterogeneous taxonomy, however, does not seem to be systematically justified by any evident semantic or syntactic correlate. In this paper, it is shown – on the basis of data from the main prose texts of this period – that wanta exhibits the same interpretive flexibility as embedding Present-Day German weil (viz. a propositional and a speech-act related reading) and that at least its function as a subordinating conjunction can, in most cases, be disambiguated by means of diagnostic tests (e. g., the predicates it introduces can resume cataphoric main-clause pronouns and appear in topicalized positions). The aim of the present contribution is therefore twofold: in the first place, to descriptively address the strategies for the expression of causation in Old High German; in the second place, to provide a precise syntactic categorization for Old High German wanta as a complementizer that may be of help to historical syntacticians who analyze clause phenomena in the above mentioned sources; finally, to address the methodological problem related to the categorization of non-disambiguable occurrences of wanta .