The purpose of the present study was to clarify the determinants of pre-service teacher’s knowledge on sexual minorities and of confidence in the accuracy of knowledge. We investigated their accurate knowledge on sexual minorities, confidence in it, opportunity to gain it and task value, and examines the relationship to one another. Ninety pre-service teacher completed a questionnaire. The main results were as follows: (1) Amount of accurate knowledge is related to confidence in the accuracy of knowledge; (2) A group with a large accurate knowledge amount has more opportunities to obtain information by manga and acquaintances than a group with a small accurate knowledge amount; (3) A group with a large accurate knowledge amount has more practical value of use for learning about LGBT.