A crossover blinded trial was used to assess the efficacy of a hydrolysed soya diet in managing cats with chronic, idiopathic gastrointestinal disorders. A commercial feline prescription diet was used for comparison. Cats that fulfilled the selection criteria were recruited and assigned randomly to one of two groups. Group 1 was fed the hydrolysed soya diet (n=5) and group 2 (n=5) received the comparison diet. Duodenal and colonic endoscopic biopsies were collected from all cats for histopathological assessment. A good response to dietary manipulation was indicated by cessation of presenting signs. Cats failing to improve after feeding the initial diet were switched to the other diet. Seven out of ten cats significantly improved while on the test diet while three cats responded well to the comparison diet but this difference was not statistically significant (p>0.05). These results suggest that a hydrolysed soya-based diet can be effective in the management of cats with chronic gastrointestinal signs.