The aim of this study is to identify the effect of creative drama-supported problem-based learning approach on self-efficacy ability of the students in the geometry classes. The pretest-posttest control group experimental design has been used in this research. The study group has been chosen from 59 students studying in 5/F and 5/E classes at an elementary school in Bartin/Turkey in 2017-2018 education years. After grouping analysis, 42 students were involved in the study group consisting of 21 students in experimental and 21 students in control groups. The experiment has lasted for six weeks. "Self-efficacy in Geometry Scale" has been used as the data collecting tool. The data has been analyzed using SPSS 20.0 programme. Parametric tests paired samples t test and independent samples t test have been used because of the homogeneity and regularity of the data. According to the evidence, it has been found out that the creative drama-supported problem-based learning approach had positive effects for self-efficacy abilities of the students who have been in the experimental group when compared to the other students in the current curriculum. Depending on the outcome of the study, it has been suggested that the creative drama supported problem-based learning could be used in other lessons and different subjects.