The article considers self-efficacy in the context of professional development of the postgraduate students at the military school. It shows the adjuncts' self-efficacy as belief in their capabilities to exercise control over their professional work in general and research work in particular. Beliefs in personal cognitive efficacy influenced the officers' choice to enter postgraduate courses and to write a dissertation. It determined their level of motivation, quality of learning, vulnerability to stress. Military specialists must have a robust sense of efficacy to succeed in their professional activity and in research. The purpose of the present study was to investigate what self-efficacy beliefs the postgraduate students have and how self-efficacy influences their professional development. Method: A questionnaire, designed in the format of Google Forms, was based on the ideas of self-efficacy as stated in Reference Framework of Competences for Democratic Culture. 21 postgraduate students participated in the study all being officers of Ryazan Guard Higher Airborne Command School. The results of the study showed a correlation between the postgraduate students' self-efficacy and their professional development. The highest level of self-efficacy and professional development, motivation for academic research was demonstrated among the postgraduate students who already had some positive professional and research experience, had scientific papers published, saw other adjuncts defending their dissertations successfully, who had certain support of research supervisors and academic society. University professors having a high sense of academic achievements and teaching capabilities can motivate postgraduate students for hard work and enhance their professional development.