Background Understanding the perceptions regarding what constitutes a "good death" among cancer patients and their families could help healthcare teams to ensure proper palliative and supportive care. Objectives To demonstrate and compare the wishes cancer patients and the perceptions of their relatives regarding end-of-life care, and to identify factors associated with patients' preferences regarding place of death. Methods A sample of cancer patients and their relatives who attended the Srinagarind Hospital (Thailand) oncology clinic or day chemotherapy from September 2017 to August 2018 were enrolled. Questionnaires were given to the participants, in which the patients were asked to respond based on their own end-of-life preferences, and relatives were asked to imagine how the patients would respond to the questions. Results One hundred eighty pairs of patients and relatives were recruited. Respondents in both groups placed importance on place of death, relationship with family, physical and psychological comfort, and relationship with the medical staff. Both groups generally agreed with the statements on the questionnaire (10/13 statements). Relatives underestimated the preferences of the patients in 3 areas: “not being a burden to others,” “preparation for death,” and “physical and psychological comfort.” Being married (adjusted odds ratio (AOD) 6.4, 95%confidence interval (CI) 1.1,36.5), having had more than 6 years of education (AOD 6.5, 95%CI 1.8,23.7), having lung cancer compared to colon cancer (AOD 12, 95%CI 1.2,118.7), duration after cancer diagnosis (AOD 0.9, 95%CI 0.93,0.99), previous hospital admission (AOD 5.7, 95%CI 1.5,21.2), and life satisfaction (AOD 17.6, 95%CI 2.9,104.9) were factors associated with preference for home death. Conclusion Thai cancer patients and their relatives indicated similar preferences with regard to what constitutes a good death and patients' wishes for their end-of-life period. However, the patients' relatives underestimated the importance patients placed on statements in three domains. Factors that influenced a preference for a home death were identified.