OBJECTIVES: To evaluate the reliability and validity of the Thai translation of the KDQOL-36 questionnaire, by focus on kidney disease specific dimensions. The KDQOL-36 consists of SF-12, and 3 dimensions of kidney disease questionnaires (the Symptom/ Problem list, Effects of Kidney Disease on Daily Life, and Burden of Kidney disease). METHODS: Subjects were 167 hemodialysis patients and 62 peritoneal dialysis patients. Reliability was evaluated by using intraclass correlation coefficients (ICCs) for test-retest reliability assessment with face to face interview and Cronbach’s alpha for internal consistency. Construct validity was supported with convergent and discriminant validity using correlation between SF-36, EQ-5D, VAS parameter and 3 dimensions of kidney disease questionnaires. Statistical analysis included descriptive statistics, Mann-Whitney U test, and Cronbach’s alpha. RESULTS: Construct validity was satisfactory with the significant difference less than 0.001 between two groups (lowest through 25 percentile and higher than 75 percentile). The reliability coefficient for the Cronbach’s alpha of the total scale of the KDQOL-36 were greater than 0.700 for all domains, range from 0.706 to 0.827. ICCs ranging from 0.713 to 0.999.  CONCLUSIONS: The KDQOL-36 (Thai) is an appropriate tool for quality of life assessment and routine care in dialysis patients.