Teacher nominations of students are commonly used in gifted and talented identification systems to supplement psychometric measures of reasoning ability. In this study, second grade teachers were requested to nominate approximately one fourth of their students as having high learning potential in the year prior to the students' participation in a randomized control trial of an advanced mathematics curriculum intervention. Treatment students completed researcher-developed unit pretests and posttests intended to measure higher order conceptual mathematical problem solving. Results from multilevel analyses indicate that third grade treatment students who were nominated during second grade significantly outperformed their un-nominated peers on these posttest measures, after controlling for students' composite reasoning scores and pretest scores. This finding supports the view that teachers perceive student qualities beyond cognitive factors that facilitate student success with atypically challenging mathematics content, reinforcing prior recommendations to include teacher nominations as one component of gifted and talented identification systems.