This research investigates the perspective taking process in online and face-to-face mediations. In particular, it addresses the question whether a perspective taking technique—being asked circular questions—helps the establishment of mutual understanding and interpersonal trust between negotiators in online and face-to-face mediation settings. This question was studied in an experimental setting in which disputants had to solve a conflict face-to-face or online by the help of a professional mediator. During the interventions, the mediator either posed mainly circular (perspective-taking) or linear questions. It was expected that mediations in which circular questions were used would lead to a higher level of mutual understanding and interpersonal trust between the disputants, and—as a result—to a more satisfying, integrative agreement. Furthermore, this study examined whether the communication mode of the intervention (online, face-to-face) affected the re-establishment of disputants’ interpersonal trust and understanding. The results of the study show that disputants’ feelings of trust in and understanding of their interaction partner improved more in the face-to-face mediations than in the online mediations. These improved feelings of understanding and trust also predicted how satisfying and integrative disputants perceived the agreement to be. Moreover, disputants perceived their mediator to be more trustworthy and more professional in the face-to-face than in the online interventions. No effect was found for mediators’ questioning style on disputants’ improved interpersonal trust and mutual understanding. We discuss the effects of the questioning style of a mediator and conclude with reflections on reasons why these effects did not lead to differences in mutual understanding and interpersonal trust between the disputants.