This study compares health-related quality of life (HRQOL) in significant others of patients dying from lung cancer, with a general population sample. Further, it explores the course of HRQOL from diagnosis (T1), at a time point close to the patient's death (T2), and six months after the patient's death (T3). The group comparisons at T1 showed that the significant others scored significantly lower on the scales in the mental domain compared with a general population sample. These results were the same at T3, when the significant others also scored lower on most of the scales in the physical and social domains. In the longitudinal analyses, there were significant changes in four scales, and three patterns of change were identified: a decrease-increase pattern for 'self-rated health' and 'positive affect'; a constant decrease pattern for 'family functioning'; and a decrease-stable pattern for 'satisfaction with family functioning'. Thus, living with inoperable lung cancer in the family and then facing the death of a family member affects most of the HRQOL dimensions.