Mathematical communication plays a very important role in learning mathematics, so it needs to be developed in mathematics learning. Mathematical communication is the process of conveying mathematical ideas to obtain a shared understanding between those who give and receive information. This study aims to describe the mathematical communication profile of prospective mathematics teachers based on self-efficacy in solving probabilistic problems. By solving probabilistic problems, it can improve probabilistic thinking, so that probabilistic problem solving can improve the ability to think at a higher level or Higher Order Thinking Skill, which is urgently needed today. This qualitative research is a study case. Subjects in this study were prospective mathematics teachers selected based on self-efficacy. The instruments used in this study were written tests and guided interviews based on probabilistic problems. Then the subjects were interviewed based on their work on the assignment. Data collection techniques are done through observation, interviewing, and documentation, while the data analysis technique used by researchers uses the Miles and Huberman model, namely by the process of (1) reduction data, (2) presentation data, and (3) drawing conclusions and verification. The results showed that prospective mathematics teachers who had different self-efficacy in solving probabilistic problems had different mathematical communication skills.