The purpose of this study was to develop and evaluate the validity of a food frequency questionnaire for Korean adolescents (FFQ-A) which could be used in clinical and epidemiological studies of the lifestyle and health of young people. The FFQ-A was designed to reflect the eating pattern of Korean adolescents, and was based on the 1998 Korean National Health and Nutrition Survey Reports. The FFQ-A had 25 (food categories. A total of 125 subjects (aged 13 to 15 years) was recruited from a randomly chosen middle school in a middle-income neighborhood in Anyang, South Korea. Each subject completed a FFQ-A, as well as a three-day dietary record. Data from 117 subjects (boys 47, girls 70) was used in the final analyses. Data on the nutrients was analyzed to estimate the Pearson correlations, Spearman rank-order correlations and agreement with categories. The validity of the FFQ-A was assessed relative to a three-day dietary record. The Pearson correlation coefficients for all the subjects were 0.94, 0.87, 0.77, 0.79, 0.49 and 0.68 for energy, carbohydrate, protein, fat, calcium, and iron, respectively. Similarly the Spearman rank-order correlation coefficients were 0.94, 0.85, 0.79, 0.81, 0.46, and 0.77 for energy, carbohydrate, protein, fat, calcium and iron, respectively. The Kappa values for energy, carbohydrate, protein, fat, calcium, and iron were 0.88, 0.67, 0.63, 0.67, 0.26, and 0.59, respectively. The percentage for misclassification of the lowest quartile into the highest quartile or vice versa ranged from 0% (energy, carbohydrate, or fat) to 16.7% (Vitamin C). Therefore the FFQ-A has a reasonable ability to assess the energy, carbohydrate, protein and fat intakes as estimated from a three-day dietary record of Korean adolescents. (Korean J Community Nutrition 8(2) : 142∼159, 2003)