This study examines the quality of life (QoL) of older adults with cancer (N = 176), by comparing them with age- and gender-matched groups without cancer (N = 176), and investigates factors associated with their QoL. The results of Medical Outcome Study Short Form-36 (MOS SF-36) showed that the study group had significantly lower scores than the noncancer group on all eight scales and on the Physical Component Summary and the Mental Component Summary. Comparison with gender and age groups revealed some differences. Optimism and social support were positively related to QoL while comorbidity, cancer-related concerns, and financial worries were inversely related.