The aim was to investigate the influence of age and gender on quality of life (QoL), complaints, and the presence and nature of self-reported diseases in persons aged 75 and older with cancer (n = 150), compared to a matched group without cancer (n = 138). A second aim was to investigate factors associated with poor QoL in people aged 75 and older. QoL was measured with Short Form (SF-12) and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-30). The study showed that the cancer group had lower (poorer) scores in different domains of QoL, more complaints, and more self-reported diseases than the group without cancer. In both groups, oldest old persons had more complaints than the youngest old. The cancer group had significantly more complaints than the noncancer group. In the youngest old, the cancer group had significantly more complaints than the comparison group. Women with cancer reported the poorest QoL compared to men with cancer and women without cancer. Receiving help for daily living from others and degree of complaints were associated with poor QoL for both the physical and mental component scores (PCS, MCS) of the SF-12. Thus, caregivers should be aware that the most vulnerable cancer patients are women, and that the complaints by cancer patients have implications for QoL especially among the youngest old.