Purpose: To examine the factor structure and measurement invariance of the Körperkoordinations Test Für Kinder (KTK) and covariates of motor competence in a sample of Iranian children aged 5-14 years. Methods: Participants were children aged 5-14 years (N = 432, 61% boys). Age, sex, and body mass index were collected. Confirmatory factor analysis (CFA) was conducted to investigate the factorial structure of KTK and multigroup CFA carried out to test measurement invariance across sexes and age groups. In addition, we calculated a model with covariates to identify the association between KTK items with age, sex, and body mass index z score. Results: CFA supported the construct validity of a one-factor model with an appropriate fit indices that the four subtests loaded on the same factor namely motor competence. Furthermore, according to the magnitude of changes in root mean square error of approximation and comparative fit index between nested models, the assumption of KTK measurement invariance across age-groups and sex were valid. Finally, adequate fit indices were found for the multigroup CFA path model of KTK with the covariates sex, age, and body mass index z score. Conclusion: The KTK is a valid, reliable, and valuable instrument for assessing motor competence of Iranian children and adolescents