This study investigated the relationship between academic achievement and temporal discounting, a behavioural measurement of delay of gratification abilities, in N=638 12-18 year old adolescents. Neuroscience studies have demonstrated protracted development of the brain areas involved in delaying immediate gratification. This finding may have consequences for educational practice, as students are frequently required to forsake attractive short-term rewards in favour of less attractive academic long-term alternatives. Results showed that adolescents with an increased ability to delay gratification achieved higher grades. This relationship was mediated by academic motivation, showing that the effect of delayed gratification abilities on grades was most effective when academic motivation was high. Our results show that the ability to delay gratification may be an individual difference variable that distinguishes high achieving students from their peers. It also highlights that understanding the development of neurocognitive processes contributes to understanding of ways in which we can influence academic success. © 2012 Elsevier GmbH.