The aim of this study was to assess whether the recently developed Diet Quality Index-International (DQI-I) was useful to evaluate the diet quality of a young Mediterranean population. A cross-sectional nutritional survey was carried out in southern Spain (Granada-Andalucia) from 2002 to 2005. Dietary information (24 h recall and FFQ) and socio-demographic and lifestyle data were collected from a representative sample of the population (n 288, 44·1 % females and 55·9 % males) aged 6–18 years (mean 12·88 (sd 2·78) years). DQI-I was designed according to the method of Kim et al. modified by Tur et al. for Mediterranean populations. It focused on four main characteristics of a high-quality diet (variety, adequacy, moderation and overall balance). This young population from southern Spain obtained 56·31 % of the total DQI-I score, indicating a poor-quality diet. A higher score was associated with a longer breakfast and greater physical activity. The DQI-I may require further modification for application in Mediterranean populations, differentiating between olive oil and saturated fats, among other changes. Further research is needed to develop a new diet quality index adapted to the Mediterranean diet.