This study compared the health-related quality of life (HRQOL) of family members of patients who participated in a program of palliative care (intervention family members) with those in conventional care (control family members). The HRQOL was measured by the short-form (SF-36) health survey questionnaire, including eight subscales. The longitudinal intervention study includes two sites: Trondheim, Norway and Malmo, Sweden. Our first hypothesis was that the HRQOL of the family members would deteriorate over time in the terminal phase and reach a low point a few months after the death of the patients, and thereafter gradually increase. This hypothesis was fully supported by the trajectories for the five scales, role limitation due to physical problems, vitality, social functioning, role limitation due to emotional problems, and mental health; but only partially so for the remaining three scales, physical functioning, bodily pain, and general health perception. From a second hypothesis, we expected the trajectories of the HRQOL scale scores for the two groups to show an increasing difference over time in quality of life in favor of the intervention group. This was the case for two of the scales: role limitation due to emotional problems and mental health. Before we may reach a definitive conclusion on the effects of palliative care programs for the HRQOL of family members, we need further longitudinal intervention studies with large samples.