The purposes of this descriptive research were to explore end-of-life decisions of Thai Buddhist patients and their families and reveal values underlying their end-of-life decisions. The 210-Thai Buddhists aged 40 years or above were recruited systematic randomly. The sample comprised three groups: 70 chronically-ill patients, 70 patients' families who had and who had no experience in end-of-life decisions. The research instrument was the Demographic Data Form and the Values Underlying End-of-Life Decisions Interview Form with a short vignette of each end-stage patient. The instrument was tested for face validity and employed test-retest reliability: the Content Validity Index and the percentage of agreement index were 0.88 and 0.90, respectively. Data were collected using face-to-face interviews and analyzed using descriptive statistics and content analysis. The results showed that: More than half of the Thai Buddhist patients and their families (51.9%) decided to forgo life-sustaining treatment. Almost one-third of them allowed the physician (18.1%) or family (10.5%) to make the decisions for them. Only 19.5% decided to continue the treatment. The most important values for continuing and forgoing the treatment were hope (92.7%) and becoming free from suffering (47.7%), respectively. Respect was the most important value for Thai Buddhists who allowed their physician or family to make the decision for them (84.2% and 59.1%, respectively). The findings indicated that it is important for health care team to recognize patient's preferences and values, patientautonomy and self-determination, and support the patients' end-of-life decisions.