Little research has been conducted on the effect of self-reported rating of symptom severity on quality of life (QoL) among cancer survivors. The aim of the study was to examine the prevalence of symptoms and whether information about self-reported symptom severity adds value to QoL measurements. Material and methods. A questionnaire including the EORTC QLQ-C30 and an empirically derived symptom check-list was completed by 2 486 cancer survivors participating in a rehabilitation program at baseline and at 1, 6 and 12 months' follow-up. We used multivariate linear regression models to evaluate the association between QoL and the dichotomous variables for perceived symptom severity (high vs. low) and cancer stage (high vs. low), with adjustment for age, gender, education and time since diagnosis. Results. Of the 2 379 participants who reported having one or more symptoms, 1 479 (62%) considered the reported symptom to be severe. This subgroup had significantly poorer QoL at baseline for all sites, ranging from -15.9 to -10.2, compared to those who did not regard their symptom as severe. Significantly lower baseline levels on all functional subscales were seen for all sites in association with high perceived symptom severity (range from -9.9 to -3.0 (physical functioning), from -21.1 to -13.0 (social functioning), from -18.8 to -8.5 (emotional functioning), and from -18.4 to -9.6 (cognitive functioning). The impairment of physical, social, emotional, and cognitive functioning persisted through 12 months for participants with cancer of the breast, lung and those with lymphomas, although not all reached significance. Discussion. Cancer survivors, irrespective of cancer site, experience a high burden of symptoms. Thorough monitoring and assessment of symptoms and careful scrutiny of cancer survivors' perceptions of how symptoms affect their lives is critical for clinical identification of patients who might benefit from enhanced medical attention and may be an important supplement to QoL measures.