Veterinary diclofenac has been responsible for the devastation of three species of Gyps vulture on the Indian subcontinent, and it is now regarded as one of the worst environmental ontaminants in the recent past. While measures have been taken to control the manufacture of veterinary diclofenac in South Asia, the promotion of diclofenac on the African continent poses a risk to vultures in this region. In Southern Africa, the species of greatest conservation concern is the Cape Griffon Vulture (Gyps coprotheres), as only 2900 breeding pairs remain in the wild. The objective of this study was to test if this species is toxicologically sensitive to diclofenac. In a single dose-toxicity study, two adult Cape Griffon Vultures with severe injuries, that were considered to have a very poor prognostic outcome, were dosed intravenously with diclofenac at 0.8 mg/kg. The changes in the clinical pathology were compared to the normal reference range established for 24 healthy Cape Griffon Vultures. Both birds died within 48 h of dosing. The clinical signs, clinical pathology, gross pathology and histopathological finding were typical for diclofenac toxicity. It would appear that the sensitivity of the Cape Griffon is similar to that of their Asian counterparts and the African White-backed Vulture (Gyps africanus). Diclofenac is almost certainly toxic to all Gyps vultures species and strong efforts must be taken to ensure that veterinary diclofenac products are not licensed or introduced to the African continent. Keywords: Diclofenac, Gyps vultures, Cape Griffon Vulture, Toxicity, Gout, Asian vulture crisis, Gyps coprotheres.