The aim of this paper is to show that the relative order of Genetive and governing noun is determined, at least in Attic literary prose of ca . 400 B. C., by a syntactic rule, according to which, Ablative or Partitive Genetive follows the main noun, and Possessive Genetive goes before the modified noun. A selection from Lysias, Thucydides, Antiphon, Andocides, and Pseudo-Xenophon’s Resp. Ath . has been taken into account for the purpose. The syntactic determination of Greek word order being at any case taken for granted, a set of lexical rules is previously established in order to give a sounder account of the evidence; in the author's view, the disproving instances are due either to emphatic reasons or to the overlapping of two rules. A second class of lexical rules can be inferred from the position of the article. May the proposed syntactic rule be right, Classical Greek is a VO language as well an OV one.