Purpose: the Thai PPS Adult Suandok tool was translated from the Palliative Performance Scale (PPSv2) and had been used in Chiang Mai, Thailand for several years. Aim: to test the reliability and validity of the Thai translation of PPSv2. Design: a set of 22 palliative cases were used to determine a PPS score on Time-1, and repeated two weeks later as Time-2. A survey questionnaire was also completed for qualitative analysis. Participants: a total of 70 nurses and physicians from Maharaj Nakorn Hospital in Chiang Mai participated. Results: The Time-1 intraclass correlation coefficient (ICC) for absolute agreement is 0.911 (95% CI 0.86-0.96) and for consistency is 0.92 (95% CI 0.87-0.96). The Time-2 ICC for agreement is 0.905 (95% CI 0.85-0.95) and for consistency is 0.912 (95% CI 0.86-0.96). These findings indicate good agreement among participants and also were somewhat higher in the Time-2 re-test phase. Cohen's kappa score is 0.55, demonstrating a moderate agreement. Thematic analysis from the surveys showed that 91% felt PPS to be a valuable clinical tool overall, with it being 'very useful' or 'useful' in several areas, including care planning (78% and 20%), disease monitoring (69% and 27%) and prognostication (61% and 31%), respectively. Some respondents noted difficulty in determining appropriate scores in paraplegic patients or those with feeding tubes, while others found the instructions long or difficult. Conclusion: the Thai PPS Adult Suandok translated tool has good inter- and intra-rater reliability and can be used regularly for clinical care. © 2012 The Author(s).