INTRODUCTION Multimorbidity is a major issue in primary health care. AIM To determine the prevalence of multimorbidity and polypharmacy in one general practice in relation to age, sex and socioeconomic deprivation in Māori and Pacific patients. METHODS A cross-sectional study using data manually extracted from electronic medical records was conducted using a stratified random sample of Māori and Pacific patients aged ≥ 35 years who were enrolled with a large urban Dunedin general practice. The data were analysed to identify the number and type of morbidities, and prevalence of multimorbidity and polypharmacy in relation to age, sex and socioeconomic deprivation. RESULTS Half (52.5% [95% CI 44.5-60.4]) of Māori and 64.3% (95% CI 51.9-75.4) of Pacific patients had multimorbidity; 22.8% (95% CI 16.6-30.1) of Māori and 10.0% (95% CI 4.1-19.5) of Pacific patients had physical and mental health co-morbidity. Fewer (13.6% [95% CI 8.7-19.8]) Māori than Pacific patients (32.9% [95% CI 22.1-45.1]) had polypharmacy. The prevalence of multimorbidity in both Māori and Pacific patients increased with age and with increasing levels of socioeconomic deprivation. The eight most prevalent chronic conditions in both Māori and Pacific patients were obesity, anxiety or depression, hypertension, asthma or chronic obstructive pulmonary disease, gout, diabetes, cardiovascular disease and osteoarthritis. CONCLUSION The high prevalence of multimorbidity in Māori and Pacific patients requires the New Zealand health system to deliver culturally competent primary health care and to re-orientate health-care delivery around multimorbidity.