Objective: To determine the association between major dietary patterns characterized by factor analysis and risk of depression and anxiety symptoms among adolescents. Design: Diet and symptoms of depression and anxiety were assessed in a crosssectional survey among students attending junior high school. Dietary patterns were derived from a self-reported FFQ, which consisted of thirty-eight items. Anthropometric measurements were also performed. Setting: Four junior high schools in Bengbu city, China. Subjects: A random sample of 5003 adolescents, 11-16 years of age (mean 13?21 years). Results: Three major dietary patterns were identified in the study based on factor analysis: 'snack', 'animal food' and 'traditional'. The prevalence of depression symptoms, anxiety disorders and the coexistence of both were 11?2 % (560/5003), 14?6 % (732/5003) and 12?6 % (629/5003), respectively. After adjustment for potential confounders, adolescents in the highest tertile of snack dietary pattern scores had a higher odds for 'pure' psychological symptoms ('depression without anxiety', OR 5 1?64; 95 % CI 1?30, 2?06; and 'anxiety without depression', OR 5 1?87; 95 % CI 1?51, 2?31) compared with coexisting depression and anxiety (OR 5 1?93; 95 % CI 1?54, 2?43). Similar to snacks, high consumption of animal foods was associated with a higher risk of psychological symptoms. Compared with low consumption, adolescents in the highest tertile of traditional dietary pattern scores had lower odds for 'pure' depression (OR 5 0?38; 95 % CI 0?30, 0?49), 'pure' anxiety (OR 5 0?85; 95 % CI 0?69, 1?04) and coexisting anxiety and depression (OR 5 0?50; 95 % CI 0?39, 0?63).