Background: Camouflaging behavior is often defined as using strategies to hide autistic characteristics. In this study, we investigated how to measure camouflaging behavior by performing a conceptual replication of the original study of the Camouflaging Autistic Traits Questionnaire (CAT-Q) and testing whether the self-reported camouflaging behavior is measuring the same construct as the second most used manner to measure camouflaging behavior, the discrepancy method. Method: In total, 674 individuals (356 autistic) aged 30–92 years, filled out the Dutch translation of the CAT-Q (CAT-Q-NL) and the Autism Spectrum Quotient (AQ). In 90 autistic adults the Autism Diagnostic Observation Schedule (ADOS-2) was administered. We executed preregistered analyses (AsPredicted #37800) to investigate the factor structure, measurement invariance, internal consistency, convergent validity and group differences. Results: Our analyses showed that the original three-factor structure had an acceptable fit and internal consistency ranged from sufficient to good. However, there was no measurement invariance between autistic and non-autistic individuals and correlations between CAT-Q-NL-scores and the discrepancy between AQ and ADOS-2 varied between low to mediocre (r = 0.04 to.28). Conclusions: The CAT-Q-NL can be used to measure camouflaging between and within autistic adults, but not between autistic and non-autistic adults and its convergent validity is limited. Despite these caveats, the CAT-Q-NL can serve as a useful addition to the clinical assessment toolbox because gaining insight in the level of camouflaging of autistic adults may help provide better mental health care. However, more research is needed into how to optimally measure the camouflaging construct.