The lessons related to mother tongue education in schools are given by classroom teachers in primary school and by Turkish teachers in secondary school. In this sense, it is necessary to include courses that will contribute to the good and effective use of the mother tongue in Turkish and classroom teaching undergraduate programs. It can be said that the practice hours in undergraduate programs should be increased in order to improve the prepared speaking skills of teacher candidates. In addition, determining the prepared speech performance levels of teacher candidates is also important in terms of the quality of practice activities. In this way, the teacher candidate can have information about their state and keep track of their development. Accordingly, the aim of this study was to develop a rating scale for the evaluation of teacher candidates' prepared speaking skills. For that reason, the research was designed according to the screening model. The study group of the study consisted of the third-year students of the Turkish Education department who were studying at the education faculty of a state university and took the "Speaking Education" course in the spring semester. In order to determine the validity of the measurement tool, the scope and criterion validity were examined. In order to determine the reliability of the assessment tool, Kendall's W test and variance analysis were applied to the evaluations of three different independent raters. Results of study obtained within the scope of validity and reliability studies are strong evidence showing that the rating scale is valid and reliable.