A topic that has aroused considerable interest in research on negotiators behaviour during the conflict management process is related to the study of the personality characteristics of Are subjects, which may be contributing to the success or failure of the process in question. Thus, this study's main objective was to examine to what extent the personality factors in the Five Factor Model (Agreeableness, Openness to Experience, Conscientiousness, Extraversion and Neuroticism) may influence the effectiveness of the negotiation and styles of conflict management (Integrating, Avoiding. Compromising, Dominating and Obliging). The main results of the study, using a sample of 255 subjects, show that the style "Integrating" is positively related to all personality factors considered, except for the "Neuroticism" factor. Moreover. the styles "Avoiding" and "Compromising" are positively related to "Agreeableness", while "Dominating" is negatively related to the latter personality factor. "Extraversion", "Agreeableness", "Openness to Experience" and "Conscientiousness" would be the personality factors that best predict effective negotiation performance.