Background: Today, teachers' self-efficacy is one of the most important issues in education. On the other hand, studies have shown that ethics and professional development play an important role in self-efficacy. Therefore, the aim of the present study was to predict self-efficacy based on professional ethics and professional development. Method: The method of the present study was descriptive-correlation and applied in terms of purpose. The statistical population was all student-teachers of Farhangian University of Isfahan province in the academic year 2009-2010. Based on Morgan and Krejcie (1990) table, 150 people were selected as a research sample by random sampling method. The research instruments were Martin (2003) Teacher self-efficacy questionnaire, Petty professional ethics questionnaire (1995) and professional development questionnaire, the reliability of which was 0. 86 with Cronbach's test. Descriptive statistics (frequency, percentage and mean) were analyzed by Spss26 software and inferential statistics (structural equations) were analyzed by Amos24 software. Results: Data analysis showed that the path coefficient of professional development with self-efficacy is equal to 0. 54 and professional ethics with self-efficacy is 0. 69 (P <0. 05). Also, about 0. 76 of the changes in the criterion variable, i. e. self-efficacy, can be explained by "professional development" and "professional ethics. " Conclusion: It can be concluded that professional ethics and professional development have a significant relationship with self-efficacy and therefore it is necessary to pay more attention to the ethics and professional development of student physical education teachers.