Background: Negative cognitive errors are important in the etiology and treatment of youth internalizing problems, but less is known about their unique relations with anxiety and depression. Aims: The major purpose of this study was to examine associations between distinct negative cognitive errors and anxiety and depression in youth. Method: In a community sample of children and adolescents (aged 9–17; N = 278) negative cognitive errors were assessed using the revised version of the Children's Negative Cognitive Error Questionnaire (CNCEQ-R). Anxiety and depression were assessed with the Multidimensional Anxiety Scale for Children and Children's Depression Inventory, respectively. Results: The strongest predictors of anxiety were the negative cognitive errors “underestimation of the ability to cope” and “mind reading”. The strongest predictors of depression were the errors “selective abstraction” and “overgeneralizing”, with the first error explaining most variance. Analyses of age effects showed that, in comparison to adolescents, children reported higher scores on the total CNCEQ-R score, and on the errors “overgeneralizing”, “personalizing”, and “mind reading”. Conclusions: The findings underscore the importance of researching the role of distinct cognitive processing in youth with anxiety and depression and further development of the CNCEQ-R. Implications for clinical practice are discussed.