The presence of words of Maori origin in contemporary New Zealand English is regularly commented upon both by linguists and in the popular press. Such commentary is, however, generally based on intuition and observation rather than empirical analysis. This paper begins with a review of published comment from the late nineteenth century to the present on the Maori presence in the New Zealand English lexicon, and then introduces a corpus-based study of that presence from 1850 to 2000. The corpus produced was the largest yet assembled for the study of New Zealand English. Findings confirmed diachronic changes in the number of Maori word tokens and types used, in the nature of Maori words used, and claims that Maori loanwords have entered New Zealand English in two distinct waves. Reasons for these changes include demographic shifts, revitalisation of the Maori language, political and social changes, and changes in attitudes among English-speakers.