Background: Using Personal-Disclosure Mutual-Sharing (PDMS) with students transitioning to Higher Education (HE) has yet to be researched in education. Aims: In two studies, we aimed to explore the immediate effects of a Coping Oriented Personal-Disclosure Mutual-Sharing (COPDMS) intervention on first-year undergraduate students' relational and organizational identification, perceived social support availability, and self-efficacy for learning and performance. In our second study, we also aimed to examine student-perceptions of participating in a COPDMS intervention. Sample and Methods: At the beginning of induction week in both studies, first-year undergraduate students on the same degree programme at a HE provider in England received an education session where COPDMS was introduced. Students participated in a COPDMS session a few days later. During COPDMS sessions, students mutually-shared and disclosed personal information and/or stories relating to transitional experiences. Results: Across both studies, students' relational identification with staff and perceived emotional, esteemed, and informational support availability from others on the degree programme significantly increased from pre- to post-COPDMS phases. Findings relating to relational identification with other Year 1 students and perceived availability of tangible support were mixed. No significant changes occurred for organizational identification with the university and self-efficacy for learning and performance. In Study 2, five higher-order themes relating to students' perceptions of COPDMS were found: (1) emotionality; (2) personal development; (3) storytelling; (4) enhanced group processes; and (5) task appropriateness and value. Conclusions: Study findings provide evidence that COPDMS is a useful psychological intervention to deliver to students transitioning to HE. Practical considerations, limitations, and future research suggestions are provided.