The aim of this major research project was to examine the psychological processes that lead to impulsive behaviour in females with bulimia and multi-impulsive bulimia (MIB). Of particular interest was the concept of Urgency, the tendency to be impulsive when experiencing negative affect. The research aimed to bring clarity to this concept and determine whether Urgency is a predominant underlying process leading to impulsive behaviour in bulimia and multi-impulsive bulimia or whether other processes are relevant, including sensation-seeking, lacking perseverance or not thinking through risks or consequences. Study 1 aimed to explore the concepts involved in Urgency by conducting a principal components analysis of an impulsivity questionnaire, which consisted of the UPPS questionnaire (Whiteside & Lynam, 2001), and additional scales created by the investigator. Participants included 115 controls and 32 females with bulimia. Study 2 was cross-sectional, comparing scales on the impulsivity questionnaire between the females with bulimia, and 40 control participants. The results suggested that Urgency involves the tendency to display impulsive behaviour under negative affect and includes not thinking about the consequences of actions, difficulty tolerating urges and cravings and feeling regret for impulsive actions. Urgency appears to be a key pathway underlying the impulsive behaviour of individuals with bulimia and individuals with multi-impulsive bulimia, and the propensity for Urgency is particularly high in individuals with MIB. Trends also suggested individuals with MIB are more likely to lack perseverance and seek risky and exciting activities in times of distress, and have more general difficulties with perseverance. The results point to the need for further research to examine the nature of difficulties with emotion among individuals with bulimia, and highlight the importance of targeting these issues in treatment.