This article describes pathways through which trade policy change in two Pacific Island countries has contributed to changes in the food supply, and thereby to the nutrition transition. The effect of various trade policies from 1960 to 2005 on trends in food imports and availability is described, and case studies are presented for four foods associated with the nutrition transition and chronic disease in the Pacific. Trade policies (including liberalization, export promotion, protection of the domestic meat industry and support for foreign direct investment) have contributed to a reduced availability of traditional staples, and increased availability of foods associated with the nutrition transition, including refined cereals (particularly polished rice and white flour), meat, fats and oils, and processed food products. This study suggests that promoting healthier imports and increasing production of healthier traditional foods, in both of which trade policy has an important effect, has the potential to improve diets and health, in conjunction with other public health intervention.