OBJECTIVES: The Kidney Disease and Quality Of Life questionnaire (KDQOL-36) is a shorter version of the Kidney Disease and Quality of Life-Short Form (KDQOL-SF), a widely used health outcomes instrument for patients with chronic kidney diseases. The aim of this study was to validate the KDQOL-36 in haemodialysis patients in Singapore. METHODS:  Secondary KDQOL-SF (version 1.3) data collected from a cross-sectional survey of haemodialysis patients attending the National Kidney Foundation (NKF) dialysis centres from December 2006 to January 2007 in Singapore was used. The KDQOL-SF items used to construct the KDQOL-36 scales were analyzed to assess their psychometric properties. Internal consistency reliability was assessed using Cronbach’s alpha. Criterion validity of the physical component summary (PCS-12) and mental component summary (MCS-12) was assessed by examining their correlation with the PCS-36 and MCS-36 calculated from the KDQOL-SF. Item-to-scale correlation was examined and exploratory factor analysis was performed to test the scaling assumptions of the KDQOL-36.  RESULTS: Totally 394 patients (male: 55.8%; mean age [SD]: 52.4 [11.7] years) completed the survey in English. Cronbach’s α value of the KDQOL-36 scales ranged from 0.70 to 0.91. Correlation between the PCS-12 and PCS-36 was 0.75 and correlation between MCS-12 and MCS-36 was 0.80. Correlation of items with their hypothesized scales was higher than their correlation with other scales for all KDQOL-36 items. Principle component factor analysis indicated a three-factor structure for the generic items (variance accounted for: 63.8%) and a four-factor structure for the disease-specific items (variance accounted for: 62.6%). The disease-specific scales and the PCS-12/MCS-12 were weakly to moderately correlated (range of correlation: 0.28 to 0.41).  CONCLUSIONS: The KDQOL-36 appears a reliable and valid measure of quality of life for haemodialysis patients in Singapore. More research needs to be conducted to assess the construct validity of the instrument using clinical data.