Competent mathematical skills are needed in the workplace as well as in the college setting. Adults in Adult Basic Education classes and programs generally perform below high school level competency, but very few studies have been performed investigating the predictors of mathematical success for adults. The current study contributes to the literature on mathematics education of adults in Adult Basic Education by investigating the relationships among mathematics anxiety, mathematics self-efficacy, gender, and age and determining if any of the variables predict mathematics performance. Adult Basic Education students at two community colleges were given math anxiety and math self-efficacy rating scales and their placement test scores were used as the math performance values. Multiple variable analyses were performed and the study found that age, mathematics anxiety, and mathematics self-efficacy were related but mathematics self-efficacy was the only predictor of math performance. Implications for future mathematical instruction in Adult Basic Education and ideas for future research were discussed as a result of this study.