Despite emergent attempts to connect temperament to a neurobiological etiology there has been little research that focuses on the relationship between temperament and character and neuropsychological test performance. Therefore, the aim of this study is to explore the relationship between temperament, character and performance on neuropsychological tests of executive functioning. Temperament and character dimensions were operationalized according to the Temperament and Character Inventory (TCI), a 240-item measure that is based on the psychobiological theory of personality. Neuropsychological performance was measured on the University of Pennsylvania Computerized Neuropsychological Test Battery (PennCNP), which is a test of executive functioning and abstract reasoning. The PennCNP comprised a test of Motor Praxis (MPRAXIS), the Penn Abstraction, Inhibition and Working Memory Task (AIM), the Letter-N-Back (LNB2), the Penn Conditional Exclusion Task (PCET), the Penn Short Logical Reasoning Task (SPVRT) and the Short Raven’s Progressive Matrices (SRAVEN). The sample comprised 422 first year psychology students at a residential university in South Africa. The results from this explorative study showed a moderate relationship between temperament, character and executive functioning. The temperament dimensions Novelty Seeking and Reward Dependence were positively related to AIM-NM, AIM and SPVRT, and inversely related to MPRAXIS. These results validate the importance of research that investigates the relationship between temperament and character dimensions and neuropsychological performance.