Objectives: To assess the consumption of ultra-processed foods and its association with the overall dietary content of nutrients related to non-communicable diseases (NCD) in the Chilean diet and to estimate the population attributable fraction of ultra-processed food consumption on the unhealthy nutrient content. Design: Cross-sectional analysis of dietary data collected through a national survey (2010). Setting: Chile. Participants: Chilean population aged ≥2 years (n 4920). Results: In Chile, ultra-processed foods represented 28·6 % of the total energy intake. A significant positive association was found between the dietary share of ultra-processed foods and NCD-promoting nutrients such as dietary energy density (standardised regression coefficient (β) = 0·22), content of free sugars (β = 0·45), total fats (β = 0·26), saturated fats (β = 0·19), trans fats (β = 0·09) and Na:K ratio (β = 0·04), while a significant negative association was found with the content of NCD-protective nutrients such as K (β =-0·19) and fibre (β =-0·31). The content of Na (β = 0·02) presented no significant association. Except for Na, the prevalence of inadequate intake of all nutrients (WHO recommendations) increased across quintiles of the dietary share of ultra-processed foods. With the reduction of ultra-processed foods consumption to the level seen among the 20 % lowest consumers (3·8 % (0-9·3 %) of the total energy from ultra-processed foods), the prevalence of nutrient inadequacy would be reduced in almost three-fourths for trans fats; in half for energy density (foods); in around one-third for saturated fats, energy density (beverages), free sugars and total fats; in near 20 % for fibre and Na:K ratio and in 13 % for K. Conclusions: In Chile, decreasing the consumption of ultra-processed foods is a potentially effective way to achieve the WHO nutrient goals for the prevention of diet-related NCD.