A concept map is a visualisation of a group of related concepts with their relationships identified by directed arrows, which can be viewed as an externalisation of a schema encoded in a learner's long-term memory. Concept maps have become popular learning tools in various educational settings. However, the existing research has not fully explored the effectiveness of concept mapping as a learning tool nor analysed its utility as an assessment tool in mathematics. This study reports on the implementation and evaluation of a novel assessment, concept mapping, in a university mathematics course (N = 219). We investigated relationships between concept mapping performance and two major outcome variables: academic achievement and assessment self-efficacy (a two-factor measure comprising "Comprehension and Execution and Emotional Regulation"). Hierarchical multiple regression showed that concept mapping performance explains a statistically significant amount of variance in both the final exam scores and the "Emotional Regulation" factor of assessment self-efficacy after accounting for other conventional coursework assessments. The explained variance in the final exam suggests that concept mapping used as an assessment tool can detect and evaluate learners' distinct capabilities that are not discerned by conventional assessments. Hence, concept mapping's potential to assess conceptual understanding warrants further investigations. Moreover, the association with the emotional regulation efficacy measure suggests that concept mapping as a learning activity involves more positivity about the ability to succeed in facing challenges than a typical assignment. This potentially indicates more perseverance and effortful learning while actively engaged in meaning-making and the type of relational reasoning elicited by concept mapping.