The aim of this study is to identify high school teachers' commitment to school development, colleagues, the teaching profession and sense of duty. The population of this descriptive survey comprised 2,805 teachers working at 47 high schools in Elazig during the 2016-2017 school year. The study sample was selected through stratified sampling, which aims to identify subgroups in a population and ensure that their size in the sample represents their proportion in the population. The data collection tool was then distributed to 461 teachers working in 12 schools selected randomly from these strata. The data collection tool had two sections. The first had conceptual questions and the second had questions about organizational commitment behaviors. The results showed that high school teachers felt full commitment only to the teaching profession, while they "often" felt committed in other subdimensions and the entire scale. More precisely, the commitment level of science teachers to school development was higher than that of social sciences teachers. Teachers working in the city center had higher commitment to colleagues and school development than those in small towns. Teacher candidates had higher commitment to sense of duty than teachers and specialist teachers. Teachers working at vocational and technical high schools had lower commitment to school development than teachers working at Anatolian high schools, social sciences and science high schools. There was a moderate, negative and meaningful relationship between teachers' age, professional seniority, professional title and marital status. There was a high, positive and meaningful relationship between the subdimensions and the entire scale. Among the subdimensions, too, there was a moderate, positive and meaningful relationship.