Background and Objectives: Cognitive theories suggest that cognitive biases may be related and together influence the anxiety response. However, little is known about the interrelations of cognitive bias tasks and whether they allow for an improved prediction of fear-related behavior in addition to self-reports. This study simultaneously addressed several types of cognitive biases in children, to investigate attention bias, interpretation bias, memory bias and fear-related associations, their interrelations and the prediction of behavior. Methods: Eighty-one children varying in their levels of spider fear completed the Spider Anxiety and Disgust Screening for Children and performed two Emotional Stroop tasks, a Free Recall task, an interpretation task including size and distance indication, an Affective Priming Task, and a Behavioral Assessment Test. Results: We found an attention bias, interpretation bias, and fear-related associations, but no evidence for a memory bias. The biases showed little overlap. Attention bias, interpretation bias, and fear-related associations predicted unique variance in avoidance of spiders. Interpretation bias and fear-related associations remained significant predictors, even when self-reported fear was included as a predictor. Limitations Children were not seeking help for their spider fear and were not tested on clinical levels of spider phobia. Conclusions: This is the first study to find evidence that different cognitive biases each predict unique variance in avoidance behavior. Furthermore, it is also the first study in which we found evidence for a relation between fear of spiders and size and distance indication. We showed that this bias is distinct from other cognitive biases.