Impaction colic is the single most common type of colic diagnosed in a large population of donkeys (more than 2000 animals) at The Donkey Sanctuary, UK and the fatality rate from the disease is high. This paper reports risk factors for impaction colic in this population during 2006, identified using an unmatched case-control study. There were 71 cases of impaction colic and multivariable analysis identified a number of variables associated with the disease. Management factors that increased the risk of impaction included paper bedding, feeding of concentrates, limited access to pasture and increasing number of carers. In addition, health variables that were associated with an increased risk of impaction colic were weight loss, recent vaccination and a number of dental abnormalities. The implications of these associations are described and possible practical measures that might be implemented to reduce the risk of the disease are discussed.