According to the World Health Organization, the proportion of noncommunicable diseases (NCD) burden is foreseen to increase to 57% in 2020. Consumption paterns have a positive efect on healthy growth and development during childhood and adolescence, and on health problems in adulthood. Diet quality indices are mathematical algorithms used for nutritional epidemiology, aimed at quantifying the degree of adequacy between actual intakes of nutrients or food groups within a population and the reference intakes, which are established based on scientiic facts assuring an optimal state of health while preventing consumers from chronic diseases. Similarly, indexes allow to analyse dietary patern of target population and its consumption trends. In general the terms, DQI (Diet Quality Index), HDI (Healthy Diet Indicator) and MDS (Mediterranean Diet Score), are referred to three internationally recognized diet indexes, which several indices have been adapted from. This chapter includes an extensive review of existing diet indexes, 1) providing a brief description of the most relevant ones, 2) highlighting the weaknesses and strengths and 3) deining the suitable scope of application of each index.