Background: One of the most critical choices of students is to choose a university major. Lack of knowledge, towards the major causes a mismatch between the career prospects and their needs and expectations. Therefore, this study was conducted to determine the knowledge of Islamic Azad University, Tehran Medical Branch students to their educational major at the time of ثntrance to university.
 Materials and methods: This descriptive study was conducted on 501 medical and non-medical fisherman students of Islamic Azad University, Tehran Medical Branch, whom were selected by relative stratified random sampling technique. Data gathering tool was a questionnaire which consisted of two sections, including demographic information and questions to measure students’ knowledge.
 Results: The mean and standard diversion of students’ knowledge was 5.48 and 3.60, respectively. Students’ knowledge was high in 30.3%, moderate in 40.5% and low in 29.1%. The study showed that the increase in educational levels directly correlate with the knowledge. This means that with an increase in educational levels, the knowledge increases. The highest rank of knowledge, based on the educational levels, was related to professional doctoral degree with mean rating of 342.17, and the least knowledge was related to the Bachelor's degree mean rate of 136.32.
Conclusion: The findings indicated that most of students had moderate knowledge about their major at arrival to college. Therefore, it is suggested that the students have consultation about their major by schools, media, families, and… in order the students know more about their majors before entering university.
Keywords: Knowledge, Educational major, Students.