The main purpose of speaking education is to enable individuals to express their thoughts accurately and effectively in every environment they communicate. This is possible with the teaching plan and measurement tools for different speech types. This research focuses on students' persuasive speaking skills. In this study, we aimed to develop a rubric to evaluate the persuasive speaking skills of primary school fourth grade students in Turkish. The research was designed with a quantitative research method and survey design. The study group consists of 100 students studying in the fourth grade of primary school. A convenience sampling technique was used to determine the study group. The study data were collected in five weeks through the students' plan papers and persuasive speech video recordings. In this process, students were asked to choose one of the topic suggestions for persuasive speeches and to plan and present their speeches. The collected data were evaluated by two raters using a rubric prepared by consulting expert opinion. The evaluation results were analysed, and a valid and reliable rubric was created. It was decided that the rubric would consist of fourteen categories, including "planning", "attracting attention", "expressing the problem situation", "expressing the solution", "visualisation", "directing to action", "supporting and justifying thoughts", "appealing to emotions", "subject integrity", "starting and ending a conversation", "voice utilisation", "fluency", "body language" and "use of time" and three achievement levels as "high", "medium" and "low". The developed rubric can be used in lessons by primary school fourth grade teachers.