This study examined anxiety- and depression-related cognitive content in children. We developed the Children's Thought Questionnaire (CTQ) to include anxious thoughts characterized by threat and uncertainty; depressive thoughts by loss, self-deprecation, and certainty/hopelessness; and positive thoughts by interest, pleasure, and positive self-reference. The CTQ and measures of anxious and depressive symptoms were completed by 193 5th- and 6th-grade children. Exploratory factor analysis of the CTQ revealed that items loaded on 2 factors according to negative and positive valence. However, use of conceptually derived subscales demonstrated specificity, with higher levels of anxious thoughts uniquely predicting greater anxious symptoms and higher depressive thoughts uniquely predicting greater depressive symptoms. Furthermore, positive thoughts were negatively related to depressive symptoms but either unrelated or positively related to anxious symptoms, thus providing support for cognitive specificity.