Data were examined from the New Zealand Ministry of Health National Minimum Data Set (NMDS), a collection that covers all publicly funded hospital discharges, over a 20-year period from 1 January 1990 to 31 December 2009, to describe the prevalence of admissions to New Zealand public hospitals for dental care and associated time trends for people of all ages during this 20-year period. A total of 120,046 admissions between 1990 and 2009 were identified as being primarily for the provision of dental care. The rate of admission to hospital for dental care increased from 0.92 per 1000 population in the period 1990–1994 to 2.15 per 1000 population in 2005–2009. Dental admission rates were greatest in the 3- to 4-year-old age group, for Māori and Pacific people and for people in the most deprived quintile of the NZDep 2006 index. Almost one-third of people aged 18–34 years who were admitted to hospital primarily for dental care were acute admissions.