The purpose of the mix-methods action research study was to seek how the changes in students' perceptions about teacher classroom interpersonal behaviors, the four efficacy sources and mathematics self-efficacy beliefs were related. The methods used to accomplish this were: descriptive statistics, t-test, Pearson correlation coefficient statistical analyses, focus group interviews and a practical argument analysis. The investigation was three-fold: 1) determine students' perceptions of teacher classroom interpersonal behaviors and the sources of their mathematics self-efficacy changes during the academic semester; 2) investigate how those changed perceptions affected any existing relationships among and between students' perceptions of mathematics self-efficacy beliefs, Bandura's four sources of those beliefs, and teacher classroom interpersonal behaviors; and 3) reflective focus on researchers' teaching beliefs and strategies of self-efficacy within the mathematics classroom. Post mean scores indicated that perceived Verbal Persuasion as the most influential source of their mathematics self-efficacy and a significant positive relationship between Verbal Persuasion and efficacy beliefs toward future success in mathematics courses. Pearson correlation coefficient analysis revealed perceptions of teacher classroom interpersonal behaviors were shown to have significant relationships to the four sources of mathematics self-efficacy beliefs. Practical argument analysis provided evidence that the researcher's teaching beliefs were aligned with the four sources of self-efficacy. The significant relationships between Bandura's (1997) four sources of self-efficacy and teacher classroom interpersonal behaviors requires further investigation to illuminate how these relationships may affect mathematics self-efficacy.