Studies have shown that, among formerly obese individuals, the continued practice of the behavioural strategies adopted during weight loss is associated with the successful maintenance of a new lower weight. Much less attention has been focused on the psychological factors that motivate the continued use or abandonment of these critical weight maintenance behaviours. This paper reviews studies that have attempted to identify psychological characteristics that may be associated with weight maintenance and relapse in obesity. This is important because a better understanding of these factors may lead to the development of improved psychological treatments for obesity. The results of the studies suggest that a number psychological factors, such as having unrealistic weight goals, poor coping or problem-solving skills and low self-efficacy, may have an important effect on the behaviours involved in weight maintenance and relapse in obesity, and further research in this area is warranted.