The Spiritual Exercises of St Ignatius of Loyola functions as a unique program for spiritual conversion in Christianity. Despite being effective for over 500 years, there have been few formal studies of individuals’ experience of the Exercises. Based on psychological and philosophical literature on conversion through the Exercises, on practitioners’ reports, and on an Interpretative Phenomenological Analysis of survey responses and interviews with Jesuits, this research proposes a heuristic framework by which to understand the process of conversion through the Exercises as a change in the meaning system of the exercitant. The findings reveal those factors that support this change following the Exercises, and the absence of “struggle” that features in the literature. This study is a contribution to the research on conversion, validating the proposed framework.