The aim of this work is to evaluate the dependency-based annotation of EPEC (the Reference Corpus for the Processing of Basque) by means of an experiment: two annotators have syntactically tagged a sample of the mentioned corpus in order to evaluate the agreement-rate between them and to identify those issues that have to be improved in the syntactic annotation process. In this article we present the quantitative and qualitative results of this evaluation. Key Words: Basque corpus, dependency-based syntactic annotation, evaluation, annotators’ agreement-rate, Kappa agreement index.