The regeneration or disposal of deactivated heterogeneous catalysts depends on chemical, economic and environmental factors. Catalysts deactivated by fouling or poisoning can often be regenerated for use in the same or a related process. Means of regeneration, including washing, abrasion and careful oxidation followed by reduction are assessed. On economic grounds, regeneration is preferred. All catalysts eventually deactivate to the point where disposal is necessary. Component recovery or land fill disposal depends on economics and environmental factors. Methods of fixation/stabilisation of catalysts required to meet environmental legislation are assessed. The disposal of spent cracking catalyst, which contains enough metals to fail environmental standards, is used as an example.