The aim was to see whether qualitative analysis improved quantitative measurement of illness perception after heart transplant. Two methods of evaluating illness representations were compared: one quantitative (administration of the Illness Perception Questionnaire-Revised) and one qualitative (phenomenological reduction). The qualitative analysis provided greater insight into the idiosyncratic and dynamic nature of the concept of illness representations. Adjustments to the Illness Perception Questionnaire-Revised are suggested to improve the evaluation of illness perception in terms of dispersion of scores, emotional impact, coping strategies and treatment, and social support, and ultimately to enhance interventions designed to promote treatment compliance.