The study examines the direct and mediating effects of personality factors of Vietnamese negotiators on international business negotiation performance. The theory is developed regarding the three elements: Quality of communication experience, cultural intelligence and negotiation self-efficacy. This study found that quality of communication experience has a strongly positive impact on the performance. Cultural intelligence and negotiation self-efficacy have strongly mediating effects on the performance. Additionally, cultural intelligence and negotiation self-efficacy have reciprocal positive effects. Overall, this study concludes that the tested personality factors have a significance effect on the performance of Vietnamese negotiators in international business negotiation. Therefore, negotiators should focus on enhancing more experience in communication, this is vital and the first priority factor which negotiators need to gain and improve. Furthermore, they have to improve their level of cultural intelligence through accumulating more cultural knowledge and behavior interaction with unfamiliar cultural backgrounds. Cultural intelligence appears to be an indispensable factor in an international context which helps negotiators to deal with cultural barrier issues effectively. Finally, negotiation self-efficacy is important to obtain a better performance which will be ameliorated along with the support of quality of communication experience and cultural intelligence.