Schools are among the organizations that experience organizational conflict inevitably. Negotiation is one of the techniques that are used in conflict solution and management. Accordingly, negotiation skills of school principals are highly important. The purpose of the study is to analyze negotiation skills of school principals. The target population consists of 2323 teachers working at primary, secondary and high schools in Siverek, Şanlıurfa in the 2012-2013 academic year. The research sampling comprises a total of 364 participants: 151 primary, 141 secondary and 72 high school teachers that were chosen by the stratified sampling method. Personal Information Form, prepared by the researchers, and Negotiation Skills Scale, developed by Özgan, Çelik, and Bozbayındır, were used for data collection. Descriptive statistics such as arithmetic mean and standard deviation and such parametric techniques as t test and one-way ANOVA were used for data analysis. Scheffe test was carried out if the difference was found significant in one-way ANOVA. Eta-squared value in one-way ANOVA and d value in t test were examined to determine the effect size of the difference that was found significant. Results show that the negotiation skills of school principals are of average level in both grand total and Creating Reliance Environment and Defending Solution dimensions. The difference among teachers’ opinions on the negotiation skills of school principals was found significant in all dimensions of Negotiation Skills Scale for such variables as gender, number of teachers at school, asking teachers’ opinions while making decision in school and school principal’s dominant management style. However, it was significant for the seniority variable in the dimension of Defending Solution only. This result indicates that these variables affect the negotiation skills of school principals