The aim of this article is to measure the indexes of productivity of the prefix ful - and the suffix - ful in Old English adjective formation. This analysis is based on Baayen’s framework, which comprises different measures on productivity. The major sources of the analysis are The Dictionary of Old English Corpus and the lexical database of Old English Nerthus. This study of productivity allows for a diachronic perspective on the evolution of these affixes from the Old English period to the present. The main conclusion drawn from this analysis is that the suffix -ful is more productive than its prefixal counterpart, which implies that more productive patterns are still maintained in Present-day English in contradistinction to the less productive ones.