OBJECTIVE: The objective of this study is to assess the quality of life (QOL) of cancer patients and their family members over 1-year period post therapy. METHODS: We evaluated QOL in cancer patients (N = 161) (Short Form-8 Health Survey (SF-8), European Organization for Research and Treatment of Cancer 30- Item Core Quality of Life Questionnaire (EORTC QLQ-C30)), their partners (N = 110) (SF-8), and their children (N = 115) (KIDSCREEN-27) using a longitudinal design (t1: post therapy, t2: 6 months after t1, t3: 12 months after t1). Multiple regression models were employed to examine factors related to QOL. RESULTS: After cancer therapy, impairments in the patients' QOL were found primarily in emotional and social areas and also in role functions. We found the highest symptom burden in fatigue (M = 45.21), sleep disturbances (M = 41.04), and financial difficulties (M = 39.2). Partners had lower mental QOL compared with the general population at each assessment point (p < 0.05). No significant difference was found in physical QOL between partners and the general population (p > 0.05). Social support, full-time employment, tumor stage 0-2, time since diagnosis <1 year, and lower levels of anxiety and depression were associated with better QOL in patients. Full-time employment, social support, and lower levels of anxiety and depression had a significant impact on the partners' QOL. Higher levels of anxiety and depression in patients (p = 0.006) adversely influenced children's QOL. CONCLUSIONS: Family members' QOL is overall stable over time indicating the need for professional psychosocial support for those family members with low QOL. For the children, new measures are needed to better examine the experience with parental cancer.