The effect of aging in nitrogen upon the regeneration characteristics of the coke deposits on chromia-alumina catalysts has been investigated. To this end, the coked catalysts have been subjected to various treatments in nitrogen, and the chemical composition and reactivity of the deposits have been investigated. The results show that the process of aging in nitrogen gives rise to significant changes in both the composition and reactivity of the coke deposits, due to the stripping of the coke fractions with a higher volatility. This obviously has important consequences upon the subsequent regeneration, which are also discussed and tested in regeneration experiments using coked catalyst of different ages.