The Nova classification(1) categorises foods according to the degree of food processing. Ultra-processed food have undergone a high level of industrial processing and typically contain cosmetic additives(1). Increased consumption of ultra-processed food has been associated with adverse health outcomes, including obesity and chronic diseases(2). Evaluating household food acquisition according to the Nova classification allows the assessment of dietary quality within populations, a strategy of nutrition surveillance that can support the development of effective public health actions to improve dietary quality. In Aotearoa New Zealand (NZ), there is limited up-to-date information on population dietary habits and a lack of data on ultra-processed food consumption. This study aimed to: i) develop a methodology to classify food items purchased by NZ households according to the Nova food groups: unprocessed/minimally processed foods (Group 1 [G1]), processed culinary ingredients (Group 2 [G2]), processed foods (Group 3 [G3]), and ultra-processed foods (Group 4 [G4]) and; ii) to describe the proportions of unique food items purchased according to Nova. We obtained data on food items purchased by NZ households from the 2019 NielsenIQ Homescan® panel, a national dataset of approximately 2,000 households who recorded their grocery purchases over 1-year. In total, 28,824 unique items were purchased. Using barcodes, we merged the products with the 2019 Nutritrack dataset, an inventory of NZ supermarkets foods(2), to obtain the products’ ingredient lists. We followed best practices for classification according to Nova(3). Where available, the ingredient lists were used to classify products. Of the total unique products, 13,263 (46%) were matched to Nutritrack and classified based on their ingredient lists. For the remaining 15,561 products (54%), we identified whole Nielsen product categories (PC) that were exclusively associated with a single Nova group. Items classified by PC level included rice, fresh fruits, eggs and coffee beans in G1; baking powder, liquid cooking oils and salt in G2; beer and wine in G3; and margarine, carbonated soft drinks and bubble gum in G4. An additional 6,398 products were identified at this stage, representing 41.1% of the total 15,561 products without ingredient lists. We classified the remaining 9,163 items (58.9% of those 15,561 without ingredient list) based on the distribution of Nova groups for the 60% most purchased items within their PC. If the ingredient list was absent for any item under the 60% most purchased group, it was obtained from a search of online supermarkets. The final unweighted distribution of unique products purchased in NZ according to the Nova classification were 5583 (21.7%) in G1, 671 (2.6%) in G2, 3043 (11.8%) in G3, and 16466 (63.9%) in G4. Further stages of the research will estimate the energy from Nova groups derived from household food purchases in NZ, examining socioeconomic distribution and temporal trends.