Mindfulness-based interventions are effective as curative and preventative approaches to psychological health. However, the mechanisms by which outcomes are secured from such interventions when delivered in the workplace, and to a stressed workforce, are not well understood. The aim of the present study was to elicit and analyse accounts from past participants of a workplace mindfulness intervention in order to generate a preliminary model of how positive benefits appear to be secured. In-depth, semi-structured interviews were completed with 21 employees of a higher education institution who had completed an eight-week intervention based on Mindfulness-Based Stress Reduction, adapted for the workplace. Interviews invited participants to recount their experiences of the intervention and its impact, if any, on their work life. Aspects of the interview data that pertained to intervention experience and positive benefits were analysed using a version of grounded theory, leading to the generation of a provisional model of how positive change occurred. The model suggests that discrete, temporal experiences build on each other to generate multiple, positive benefits. As anticipated in mindfulness-based interventions, enhanced attentional capacity was important, but our provisional model also suggests that resonance, self-care, detection of stress markers, perceiving choice, recovering self-agency and upward spiralling may be central mechanisms that lead to positive outcomes. Understanding mechanisms of change may help support participant engagement and trust in work-based mindfulness programmes, and enhance participants' ability to apply mindfulness in their work life.