Background: We have established and/or upgraded cancer registries in four Pacifi c countries, a region where few cancer registries exist. We report age-standardised cancer incidence in Tonga (2000-2005), Fiji (2002-2005), Cook Islands (2000-2005) and Niue (2000-2005), and in Pacifi c people in New Zealand (2000-2005). Methods: In each country we identifi ed incident cancer cases by reviewing hospital discharge, death registration, cancer registration records, and pathology reports. The primary site and morphology data were coded using ICD-O, and age-standardised incidence rates were calculated. Results: Age-standardised cancer incidence rates for Pacifi c people in New Zealand (315 per 100,000 person-years in females, 379 in males) were similar to those for New Zealand overall (322 in females, 404 in males); incidence rates were lower in the Pacifi c, with rates of 195 and 151 per 100,000 person-years for females and males respectively in Tonga, 231 and 126 in Fiji, 165 and 142 in the Cook Islands, and 228 and 131 in Niue. However, some specifi c cancers were elevated in the Pacifi c including cervical cancer (16 per 100,000 in Tonga, 51 in Fiji, 17 in Cook Islands, and 26 in Niue compared with 10 in Pacifi c people in New Zealand, and 8 in New Zealand overall), liver cancer (rates of 8, 5, 19, 0, 7, and 2 respectively) and uterine cancer (rates of 24, 18, 47, 19 and 12 respectively). Conclusions: Cancer incidence in the Pacifi c is lower than for Pacifi c people living in New Zealand. Environmental rather than genetic factors are most likely to explain these patterns, and cancer incidence in the Pacifi c is likely to increase to rates similar to those in New Zealand as the region becomes more ‘westernised’. The high rates of cervical cancer and liver cancer in the Pacifi c indicate an important role of infectious disease (human papilloma virus (HPV) and hepatitis B virus (HBV)).