The present study explores what constitutes pre-service teachers' beliefs about English teaching competence, perceived English teaching competence, and actual English teaching competence, how these variables are related, and how beliefs function in self-evaluation. Eighty-eight pre-service elementary school teachers participated in the study. They were asked to perform the teaching task and respond to the surveys about beliefs and self-evaluation. The scores of beliefs, self-evaluation, and actual teaching ability were calculated and analyzed. The results are as follows: Pre-service teachers' three variables, beliefs about English teaching competence, perceived English teaching competence, and actual English teaching competence, are separate constructs consisting of different components; there are correlations between some of these components and actual English teaching competence. Also, this study revealed that one of the components--perceived competence about their skills of designing and teaching effective English lessons--best explains actual English teaching competence. Additionally, it was found that preservice teachers make some errors when they evaluate their English teaching competence, which causes tendencies such as overestimation or underestimation of their competence, and that their beliefs play a role in these self-evaluation tendencies.