In this study, we investigated to what extent indirect measures predict behavioural and physiological fear responses towards spiders. Implicit attitudes towards spiders were assessed using an implicit association test and attentional bias towards spiders was assessed using a dot probe task and a disengagement task. Results showed that a self report measure of fear for spiders, but not the indirect measures predicted avoidance behaviour. The indirect measures but not the self report measure predicted changes in heart rate in response to the presentation of a spider. These results suggest that indirect measures may be useful in predicting and understanding fear responses that are not easily voluntarily controlled.