Recent research has highlighted the utility of using revised Reinforcement Sensitivity Theory (RST) to further understand the individual differences that influence binge eating behaviours. The current study draws on both RST and theoretical models that implicate negative affect in binge eating, with the aim of identifying indirect pathways between individual differences in RST systems and binge eating as mediated through negative affect. Undergraduate students (n = 229, M = 22.67 years of age, SD = 8.95, 76% female) completed self-report measures of revised reinforcement sensitivities, negative affect and binge eating symptoms. Bootstrapped tests of indirect effects showed that negative affect mediated the pathway between the Behavioural Inhibition System (BIS) and binge eating symptoms. Additionally, negative affect mediated the pathway between rash impulsivity and binge eating symptoms. This study supports and extends previous research by highlighting the experience of negative affect as a possible mechanism through which heightened BIS and rash impulsivity leads to binge eating.