In Basque, absolutive, ergative and dative NPs can be relativized, cf. egin dudan etxea ‘the house which I built’. Other arguments are less accessible to relativization, though sometimes it is possible. In our paper, we analyze translation strategies enabling to avoid the typological constraint in question. The study is based on four Old Basque translations of the New Testament from both Spanish and French Basque Country. The basic strategy (suffix -n used for prepositional relative clauses) is indeed rarely observed with oblique cases. The relative pronouns zein ‘which’ and sometimes non ‘where’ are often used instead, especially when relativizing genitives. Two independent clauses instead of a relative construction can be used as a rare strategy. Another translators’ strategy is omitting the relative clause. It is extremely marginal, most probably because the translator deals with a sacred text, therefore, such an omission can be accounted for as an accidental error. Finally, to avoid the relativization of an oblique NP, it is possible to reformulate the original sentence using a core case instead of an oblique one. Some of the relativization strategies observed in Old Basque translations are well attested cross-linguistically.