ObjectivesThe Gothenburg Trismus Questionnaire (GTQ) is a comprehensive scale for screening and assessing trismus in head and neck (H&N) cancer and temporomandibular joint disorders (TMD) patients. This study aimed to translate and cross‐culturally adapt the GTQ in China, and to test its measurement invariance.MethodsThis study comprised 278 H&N cancer, 245 TMD, and 507 control patients. Internal consistency and test–retest reliability were tested to assess the GTQ's reliability. The validity was evaluated through composite reliability (CR), average variance extracted (AVE), and correlation tests. Multi‐group confirmatory factor analysis (CFA) was used to investigate the GTQ's measurement invariance across clinical status and gender. T tests were employed to compare score differences across clinical status and gender.ResultsThe Chinese version of GTQ scale shows excellent internal consistency and test–retest reliability. The CR, AVE, and correlation values demonstrate the good validity of GTQ. The multi‐group CFA supported configural invariance across clinical status but not metric invariance, while it supported strict invariance across gender. Additionally, t tests revealed that patients with H&N cancer and TMD scored higher than the control group, while males scored higher than females.ConclusionsThe Chinese version of GTQ serves as an effective tool for screening and assessing trismus.