Communication for Specific Purposes (CSP) is a new field which has been growing rapidly during the last three decades, devoted to researching into professional communication as well as to devising new ways of teaching how to communicate successfully. Within this field, much work has been dedicated to the communicative interaction of business negotiations, in order to investigate the aspects of language which are of relevance when negotiating. This paper aims to heighten awareness of the power of language as a negotiating instrument and it places emphasis on the dependence of language on culture, in the sense that in international business negotiations the set of rules in one party's environment must be known and understood, at least to some minimal degree, if communication with his counterpart is to be successful.