© 2020 American Psychological Association. Parent reports of child temperament, especially those of mothers', are frequently used in research and clinical practice, but there are concerns that maternal characteristics, including a history of psychopathology, might bias reports on these measures. However, whether maternal reports of youth temperament show structural differences based on mothers' psychiatric history is unclear. We therefore conducted tests of measurement invariance to examine whether maternal psychopathology was associated with structural aspects of child temperament as a means of evaluating potential biases related to mothers' mental disorder history. From 2 community-based studies of child temperament, 935 mothers completed the Child Behavior Questionnaire (CBQ) and semistructured diagnostic interviews that assessed their own lifetime history of depressive symptoms, anxiety, and substance use disorders. Mothers also completed a measure of depressive symptoms concurrent to their completion of the CBQ. We found little evidence that mothers' current depressive symptoms or history of depressive symptoms, anxiety, or substance use disorders were associated with the structure of their reports of child temperament. Thus, there is little empirical support for systematic biases in reports of youth temperament as indexed by psychometric modeling.