Māori and non-Māori rates of utilisation of cardiology inpatient services were analysed by linking the enrolled population of Partnership Health with hospital discharge data from the New Zealand Health Information Service. Rates of discharges for the 2 years ending June 2007 (n=127,246) were analysed in relation to age, gender, ethnicity (19,712 Māori), deprivation score and other variables. Rates of utilisation including cardiology in patient services were analysed by diagnosis-related groups (DRGs). Standardised Māori rates of utilisation for almost all major cardiology DRG categories were substantially higher than the non-Māori population. Overall rates for cardiology DRGs were 1.47 times higher for Māori. Standardised Māori rates were higher than the non-Māori population for higher deprivation scores. Māori cardiology inpatients had almost twice the level of Care Plus levels than the non-Māori population. The researchers stress that the higher rate of hospital utilisation suggests that higher quality data rather than increased access is the explanation.