Objective.-To examine the factor structure of the Headache Triggers Sensitivity and Avoidance Questionnaire (HTSAQ) and its German version (HTSAQ-G), in order to identify potential different types of triggers. Furthermore, a short form of the questionnaire was developed. Background.-The HTSAQ includes 24 of the most commonly reported headache triggers (eg, stress, odors, lack of sleep). Both the HTSAQ and HTSAQ-G appeared to be reliable and valid measures of sensitivity to and avoidance of headache triggers. Methods.-In a crosscountry collaboration, data from 2 cross-sectional studies including N = 391 individuals diagnosed with migraine from Australia (n = 222) and Germany (n = 169) were analyzed. The factor structure of the questionnaire was examined using exploratory and confirmatory factor analysis. Finally, a short form of the HTSAQ was constructed and evaluated regarding psychometric properties. Results.-Factor analytic results showed a differentiation between internal and external headache triggers, and different patterns of strategies in coping with triggers. The scales of both the original questionnaire as well as the developed short form showed good reliability (Cronbach's α = 0.76 to 0.96). As expected, negative correlations (r = −0.10 to −0.30, P = .006 to .044) with acceptance of pain were observed. Participants with chronic migraine showed significantly higher triggers sensitivity and avoidance of triggers than those with episodic migraine (t(389) = −9.12, P < .001, Cohens d = 0.93). Conclusions.-Both the long and short forms of the questionnaire appear to be reliable and valid measures. The development of the short form of the questionnaire simplifies the use of the HTSAQ in clinical practice. Further research should focus on other primary headache disorders, such as tension-type headache or cluster headache.