Research Findings: Trust is considered to be a crucial element of effective parent-preschool partnerships and an important prerequisite of parental involvement in their children's educational processes. The present study examines the role of child and family characteristics and aspects of parent-preschool communication in parents' trust. 735 families at 169 preschools participated in the study. All data were obtained in the context of the evaluation of a governmental preschool initiative in Germany. As well as trust, child and family characteristics were assessed using questionnaires. Aspects of parent-preschool communication were assessed with questionnaires and standardized observations. Structural equation modeling analyses indicate that a child's behavioral disorder and their family's language predict parents' trust in their child's preschool. In addition, the results highlight that the quality of informal communication during transition times is crucial in trusting relationships. Thus, all aspects of parent-preschool communication (parents' perceived quality of communication, parents' satisfaction with communication, and observed interaction quality between parents and professionals) are positively related to parental trust. Practice or Policy: Consequently, training programs should make use of these results to enhance professionals' communication strategies and thereby to establish a trustful relationship with all parents.