The study aimed at determining the Organizational Justice and its Relationship to the Principals Administrative style practiced at Post Basic education Schools in the Sultanate of Oman from the viewpoints of teachers. It also, determined whether there were significant statistical differences in the level of the organizational justice and the Administrative style practiced that could be attributed to gender, job title and experience. To achieve the objectives of the study, the literature review was conducted .A questionnaire consisting of (46) sentences divided into two areas of concern, the organizational justice and administrative styles practiced by principals . After ascertaining the veracity and stability of the questionnaire, it was applied at a random sample of (450) teachers, in four educational regions (Muscat, Batinah South, Dhakiliah and Dhofar). After processing the data statistically using the SPSS package the study highlighted the following results: - The estimates of the sample of study in organizational justice, and democratic management style were high, while their estimates in the autocratic style was low. -There was a relationship of statistical significance level (a < 0.001) between the mean estimates of the subjects in the organizational justice and democratic management style, while there was an inverse relationship statistically significant at the same level between the mean estimates in the organizational justice and autocratic management style. -There were significant differences at the level (a <0.01) between the mean estimates for the sample of study in organizational justice due to the gender variable, while there were no statistically significant differences due to the job title and years of experience variables. -There were significant differences at the level (a < 0.01) between the mean estimates of the subjects in the autocratic and democratic styles due to the gender variable and statistically significant differences at the level (a < 0.05) due to job title. While there were no statistically significant differences in democratic management style and there was no statistically significant differences in the autocratic and democratic management style due to the years of experience variable. Based on the literature and the results of the survey, the researcher suggested the following recommendations: • adoption of the remuneration of teachers within the schools declared procedures. taking into account standards of administrative practices when selecting principles. activating the role the of administrative supervisors in the followup of administrative practices in schools and the level of achievement of organizational justice. • arranging regular meetings between the Ministry of Education officials in charge of making decision and the teachers to be aware of their needs and adopt a mechanism for fulfilling them. Further, studies on Organizational Justice and its Relationship to the Schools Effectiveness were also suggested.