While there is a significant body of research concerning Catholic faith formation in a variety of educational contexts around the world, relatively little attention has been devoted to the notion of missionary discipleship as a foundation for Catholic formation. Recently, the National Catholic Education Commission, in its document Leading Formation for Mission, also elaborates a solid definition of formation and stated: ‘Formation is imaginative, creative and honours adult learning principles […] It engages the ‘intellect’ and is nurtured by appropriate theological content and it engages the ‘Spirit’ and is characterised by contemplation and action for mission’ (2022). This paper seeks to contribute to a deeper understanding of formation for missionary discipleship by presenting an evaluation of the efficacy of In Altum, a student-focussed ministry and leadership program developed at the University of Notre Dame Australia in response to the developing magisterial teaching concerning the notion of ‘missionary discipleship’. In particular, we examine participants’ personal faith development, understanding of missionary discipleship on campus, preparation for future ministry, and understanding of contemporary challenges to discipleship. The study progresses in three parts: First, it provides a brief background to In Altum, including the philosophical and sociological context, as well as the key theological principles underpinning the formation offered within the program. Second, following an overview of the mixed-methodology approach taken in the study, which details both the use of qualitative and quantitative data derived from focus groups and an online survey, the paper presents the results of the study, which sought to investigate the efficacy of the program as it pertained to the following: (a) the building of (personal subjective assessment of) faith in participants; (b) the building of participants’ understanding of, and confidence in, the task of evangelisation as missionary discipleship in a secularised context; (c) building a strengthened sense of community amongst the participants. In the third and final section, the reported strengths and weaknesses of the program are examined. The paper also comments on implications for the program on the culture of the university more broadly, including precepts of the program’s findings that may be applied in light of the Australian Catholic Plenary Council’s findings to enhance the future directions of formation programs in the Catholic University Chaplaincy, with possible application to Catholic secondary schools and parish youth groups.