The purpose of this research study was to evaluate the effectiveness of problem-based learning on the math anxiety, self-efficacy and math achievement of fifth grade students in a math class. The study was designed to implement problem-based learning in a fifth-grade math class. Data was collected using three research instruments: (a) pre- and-post test results from the District Math Assessments, (b) student interviews with a focus group of six students, and (c) classroom observations. The results from the district math assessments were compared using a paired samples t-test. The responses to the interviews were transcribed and coded in order to locate patterns and themes. Additionally, the classroom observations were coded to analyze patterns in student behaviors and their levels of engagement. An analysis of the data showed that the implementation of the problem-based learning approach does have a significant effect on students' math anxiety, self-efficacy and math achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]