Negotiation is one of the most used conflict management procedures in the school context, since through an effective solution against violence is reached. This investigation considers personal and scholars variables that can influence negotiation efficacy in conflicts between elementary school students, namely sex, school grade, number of failures, study time school goals, and evaluation. Following a quantitative approach, the sample consisted of 874 Portuguese students from elementary schools, 452 males and 422 females with ages ranged between 10 and 18 years. The instruments applied were a personal questionnaire, and the School Conflicts Negotiation Efficacy Questionnaire (SCNEQ). The results show that sex, number of failures, and study time have an influence on the students' negotiation efficacy, as well as on student´s evaluations. The limitations of the study and practical implications for conflict management in schools are also presented, namely that the development of students' negotiation abilities is relevant.