Malnutrition is a common cause of morbidity and mortality in captive giraffe (Giraffa camelopardalis). Frothy bloat, a nutrition-related disease of domestic ruminants, has not previously been reported in Giraffidae. A 10-year-old female reticulated giraffe (G. c. reticulata) had a chronic cough and died in February 2007 following a two-month period of weight loss. Multiple nutrition-related abnormalities were identified post mortem: frothy bloat appeared to have been the immediate cause of death; there was no fibrous material in the forestomachs; and rumen contents were mildly acidotic. There was also serous atrophy of multiple fat deposits and acute exudative interstitial pneumonia. The giraffe’s low (structured) fibre intake was associated with provision of ad libitum (ad lib) pelleted food, lucerne hay that had appeared unpalatable, and insufficient browse. The low fibre intake would have predisposed to frothy bloat and ruminal acidosis. Serous fat atrophy (emaciation) was probably due to inadequate overall food intake (associated with respiratory disease, frothy bloat and rumen acidosis) and increased energy demands (respiratory disease and winter temperatures). Sufficient fibre intakes in giraffe must be assured, by restricting concentrate provision and by feeding high quality, palatable roughage. Zoos should endeavour to find methods of feeding ad lib browse to giraffe.