The recent accession of Saudi Arabia to the World Trade Organization (WTO) will increase the country's participation in world trade and the Saudi market attractiveness to Foreign Direct Investment (FDI). As the opportunities for international trade grow, managers from across the globe, including those from the US will be engaged in negotiating with their Saudi counterparts. Owing to the cultural differences across these two countries, the need to understand how culture may affect various individual characteristics such as idealism, relativism, opportunism, and Machiavellianism and managers’ perceptions of unethical negotiation practices becomes very prominent for successful business negotiations. The present study assists in this endeavor. Specifically, this study compares managers from the two countries on their individual characteristics and also contrasts their impact on managers’ perceptions of various unethical negotiation tactics. Based on the data consisting of 259 US and 198 Saudi managers, the study findings suggest that managers across these two countries exhibit significant differences in their individual characteristics. Further, we also show that these characteristics have differential effects on managers’ perceptions of unethical negotiation tactics across the two countries. We highlight study contributions and also provide implications for the development of negotiation strategies capable of enhancing Saudi and US firms competitiveness.