This study aimed to analyze the relationship between spirituality, coping strategies and health-related quality of life (HRQL) among a large representative sample of patients two years after cancer diagnosis. Using a cross-sectional design, medical and self-reported data were collected by physicians and a patient telephone interview, respectively. Among 4270 participants, 54.6% reported that spirituality was not a source of comfort at all during the disease, 23.4% stated that it was a source of moderate comfort and 22.5% a source of great comfort. After adjustment for age, gender, educational level and living in a couple, a multivariate analysis showed that a lower mental HRQL score was independently associated with finding moderate comfort in spirituality when compared with finding no comfort at all. After multiple adjustment, a lower score of physical HRQL and a higher score of fighting spirit were independently associated with having found great comfort in spirituality when compared with those who found no comfort at all. This study aimed to understand the dynamics of religious beliefs among cancer patients over the disease duration and to understand how these beliefs could be considered and utilized by patients as a source of comfort and support. The results highlight not only the role spirituality may play in disease management and the extent to which it may be a valuable source of comfort during the follow-up of cancer patients, but also its role in the evaluation of the different dimensions of HRQL.