The contrast avoidance model has been proposed as a (maladaptive) emotion regulation strategy in generalized anxiety disorder, suggesting that chronic worry and anxiety play a role in maintaining a negative mood to prevent a drastic shift to negative emotions triggered by uncertain future events. This model ironically explains why individuals with generalized anxiety disorder experience persistent worry and anxiety. The Contrast Avoidance Questionnaire (CAQ) was originally developed in English to assess individual differences in contrast avoidance. In this study, we developed a Japanese version of the CAQ and tested its reliability and validity. The CAQ includes two versions: one focusing on worry (CAQ-W) and the other on negative mood (CAQ-GE). Study 1 confirmed the structural validity and internal consistency of the Japanese version of the scale. Study 2 demonstrated sufficient test-retest reliability. Study 3 examined convergent and divergent validity, and the results generally replicated the original findings. We discussed transdiagnostic clinical applications and outlined directions for future research using the CAQ.