Mathematics educators and researchers have described creativity as an essential part of mathematics, yet little research has been done to study the effects of fostering creativity in the tertiary mathematics classroom. This dissertation explores the impact of creativity-fostering instruction on student self-efficacy and motivation for mathematics in three parts. The first part presents a framework for characterizing creativity-fostering mathematics instruction (CFMI) which is used to study evidence of CFMI in association with qualitative changes in student self-efficacy for proving. The theoretical development and initial testing of a new instrument for measuring self-efficacy for proving is also outlined. The second part explores student problem posing as one particular instructional tool for fostering mathematical creativity. Through an illustrative case study of three students' experience problem posing, this study demonstrates the impact problem posing had on these students' motivation toward mathematics. The final part describes a large-scale quantitative study of CFMI, student self-efficacy, and student motivation. For this, two new instruments were developed for measuring CFMI and creative self-efficacy for mathematics. Limitations in the data collected constrained the study of the impact of CFMI on pre- to post-semester change in student self-efficacy and self-motivation. However, these methods demonstrate validity and reliability of the instrument used and provide a model for future study of the impact of CFMI on student self-efficacy and self-motivation.