<p>The present study aims to investigate the roles of both teacher and child factors in teacher-child relationships in preschools serving children experiencing poverty (i.e., attending Head Start). Specifically, we examined the relations between children’s gender, undesired behavior, teacher’s job stress, and teacher-reported teacher-child relationships. A total of 129 teachers and 635 children from collaborating Head Start centers across six U.S. states were recruited in this study. Teachers completed a set of validated online survey questionnaires that measured children’s undesired behavior, teacher job stress, and teacher-child relationships. Multilevel modeling results indicated that teachers tended to report conflictual relationships with boys and closer relationships with girls. Children’s undesired behavior was strongly and positively associated with conflict, and negatively and weakly associated with closeness, particularly for boys. Teachers’ job stress was not related to teacher-child relationship quality. Our study reveals the important role of children’s undesired behavior in teacher-child relationships and indicates that potential bias in gender-based expectations might negatively contribute to teacher-perceived teacher-child closeness.</p>