Fatal colonic obstructions were diagnosed in three captive, adult, reticulated giraffe (Giraffa camelopardalis reticulata). Clinical presentations varied, but all cases displayed decreased activity, anorexia, and considerably decreased fecal production, consistent with intestinal obstruction. Case 1 was diagnosed at necropsy with a phytobezoar obstructing the spiral colon. Case 2 was diagnosed at necropsy with a fecal impaction of the colon. Case 3 was diagnosed during surgery with colonic ileus. Cases 2 and 3 underwent surgical intervention but were markedly compromised by the time of surgery and died during surgery or 24 hr postoperatively. Gastrointestinal obstruction, requiring aggressive supportive care and early surgical intervention, should be considered in giraffe in which anorexia and substantially decreased fecal production are observed. Abdominal exploratory surgery will likely be necessary for diagnosis and treatment. Based on a small number of cases, gastrointestinal obstruction has a poor prognosis in giraffe.