Aims: This study aimed at investigating the status of polypharmacy and the experience and perception of bereaved family members of patients with advanced cancer regarding the burden of oral medication. Methods: Self-administered questionnaires were mailed to 303 bereaved family members of patients with advanced cancer, and 102 valid responses were analyzed (response rate, 33.7%). Results: The number of patients in the polypharmacy group (patients taking six or more tablets at a time) was 65 and that in the non-polypharmacy group (patients taking less than six tablets at a time) was 37. The percentage of bereaved family members who felt that the oral administration burden of patients was significantly higher in the polypharmacy group (43.1% vs. 10.8%, p<0.01). The results of the analysis indicated that the bereaved families wanted to reduce the number of tablets taken at a time for alleviating the burden of polypharmacy. The bereaved families of patients in the polypharmacy group were greatly concerned that the number of oral medications was too large. They also expressed the need for medical staff from whom they could seek explanation and counseling regarding the oral medication of patients. Conclusion: It is suggested that medical staff need to be fully aware of the concerns of patients’ families regarding drugs besides checking the compliance status.