To assess the reproducibility and validity among adults in the Southern Cone of Latin America (Argentina, Chile and Uruguay) of a self-administered FFQ to be used in the CESCAS I Study, an ongoing observational prospective cohort study to detect and follow up CVD and their risk factors, as well as in other epidemiological studies.

Relative validity of the FFQ was evaluated by comparing nutrient and selected food group intakes with those from three 24 h recalls (24HR) administered over 6 months. The FFQ was administered at baseline (FFQ1) and again after 3 months (FFQ2).

Primary-care centres in Argentina, Chile and Uruguay.

Adults (n 147) aged 21–74 years.

Reproducibility (FFQ1 v. FFQ2): the intra-class correlation coefficients for nutrients ranged from 0·52 (potassium) to 0·74 (fat). Validity (FFQ1 v. the average of three 24HR): the Pearson correlations for energy-adjusted nutrients ranged from 0·39 (thiamin and cholesterol) to 0·59 (carbohydrate). Joint classification: overall, 66 % of participants in the lowest 24HR quintile were in the lowest one or two FFQ1 quintiles, and 62 % of those in the highest 24HR quintile were in the highest one or two FFQ1 quintiles. On average, only 4 % were misclassified into extreme quintiles.

The FFQ version for the Southern Cone seems to present moderate to acceptable relative validity and reliability for its use in the CESCAS I Study to measure dietary exposure.