PURPOSE: Little is known regarding the factors associated with the willingness of family caregivers of terminal cancer patients to participate in a bereaved survey. This study aimed to ascertain the pre-loss factors that predict actual participation in a bereaved survey. METHODS: We conducted a prospective observational study using data from two multi-center surveys at the end-of-life and after loss. In order to identify the pre-loss factors associated with participating in the bereaved survey, we used a step-wise multivariate logistic regression analysis. RESULTS: Among 185 bereaved individuals, 30 responded to the survey (response rate: 16.2%). There were differences between the participation group and the non-participation group regarding religion, economic status, and perceived quality of care as assessed by the Quality Care Questionnaire-End of Life. A final multivariate model revealed that bereaved individuals who professed a religion (adjusted odds ratio [aOR]=5.01; P=0.008), had a high income (aOR=4.86, P=0.003), and satisfied with the care for familial relationship (aOR=4.49, P=0.003) were more likely to engage in the bereaved survey. CONCLUSION: Our finding suggests that improving the quality of end-of-life care may promote actual participation in a bereaved survey through easing post-loss distress. More attention should also be paid to those bereaved individuals who are hesitant to participate in a bereaved survey.