A retrospective histologic study was performed for 96 deceased bongo (Tragelaphus eurycerus) submitted to Northwest ZooPath from 1995 to 2015. Histologic data were assessed for associations with sex, age, cause of death/euthanasia, and affected organ systems. Female bongo lived significantly longer than males. Males were more likely to die from infectious causes (41.2%), whereas most females died from chronic noninfectious conditions (54.4%) and trauma/stress (28.1%). Of those that died from infectious disease, the respiratory tract was the most commonly affected organ system. The most common infectious agents included acid-fast bacteria and fungi. Chronic conditions included amyloidosis (31.0%), inanition/emaciation (23.8%), and neoplasia (21.4%). Of the 31 animals that died with amyloidosis, 58% appeared to be clinically affected, and amyloidosis was likely an underlying cause of death in 42% of the animals. The most commonly affected organs included the liver, kidneys, adrenal glands, and gastrotintestinal tract. Also noteworthy was a high prevalence of adrenal gland hyperplasia and neoplasia, cystic thyroid glands, and aspiration pneumonia, which were not consistently associated with a prior anesthetic event or other obvious predisposing cause.