End of year math scores in Texas elementary grade levels remain low. Teachers have an impact on their students' success; therefore, it is imperative teachers are confident in their ability to teach students so students can meet grade level expectations. The purposes of this study were to compare grade 3 math achievement based on gender of teacher and to investigate if teacher self-efficacy predicts grade 3 math achievement. This study was framed around the concept of teacher self-efficacy. A quantitative study approach was taken using an ex-post facto design. Survey and secondary data were collected. An independent sample t-test revealed that teacher gender made a substantive difference in the outcome of students who met grade level standards for grade 3 2018 STAAR math. A bivariate linear regression showed that self-efficacy for teaching mathematics at the elementary level did not predict the proportion of students who met grade level standards for grade 3 2018 STAAR math. Results indicated that neither gender nor self-efficacy of rural south Texas elementary teachers significantly impact the proportions of students who met grade level standards. Further research is recommended to investigate other potential factors that may contribute to why students are struggling to meet grade level mathematics standards. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]