The aim of the present study was to describe dietary patterns in a representative sample from Puna and Quebrada of Humahuaca, Jujuy, Argentina. A cross-sectional nutritional survey was carried out in a representative sample (n 1236) of individuals from these regions. For the present study, only children aged 2–9 years (n 360), adolescents aged 10–18 years (n 223) and adults aged 18 years or over (n 465) were considered. Breast-fed children, pregnant women and lactating women were excluded. Dietary data collection methods comprised one 24 h recall and a semi-quantitative FFQ. We used principal component (PC) analyses to identify prevailing dietary patterns. Multiple linear regression analyses were performed to assess the determinants of the identified dietary patterns. Two dominant PC were identified: PC1 reflected a ‘Western-like’ diet with an emphasis on not-autochthon foods. This pattern tended to be present in urban areas of the Quebrada region and was associated with a younger age, a higher level of development, and a worse diet quality. PC2 reflected an ‘Andean-like’ diet including a variety of autochthon crops. This was preferred by individuals living in rural areas from Puna with a high level of development during the post-harvest season, and was associated with a greater diet quality. These results suggest that the nutrition transition phenomenon is a reality in certain sectors of this population and might be one of the leading causes of the observed double burden of malnutrition.