BackgroundSpiritual wellbeing (SWB) is one of the crucial components of holistic care for patients with terminal illnesses. The use of a validated instrument can help health professionals approach this difficult and subjective topic. There is no validated Bengali tool to measure this domain. Our study aimed to translate the EORTC QLQ SWB32 tool into Bengali, validate it among advanced cancer patients in Bangladesh, and compare the study's findings to international validation studies to determine its suitability as a measurement and intervention tool for these patients. MethodsThe original English version of the tool was translated in Bengali and back-translated by four independent translators with good command in both languages. After approval from the EORTC translation team and linguistic validation, the tool was further validated among 163 advanced cancer patients from oncology and palliative care units of three tertiary level hospitals in Bangladesh. Reliability was tested with Cronbach's alpha, and construct validity was determined by exploratory factor analysis. Known group comparisons were performed by the Kruskal-Wallis H test and the Mann-Whitney U test. ResultTen adult cancer patients (two female and eight male, three Hindu and seven Muslim) participated in the linguistic validation. Six out of ten participants found the measure understandable and acceptable. A total of 163 advanced cancer patients participated in the psychometric validation phase. The majority of those participants were Muslims (94 %), with a slight male predominance. The internal consistency of each scale was satisfactory (0.7). Exploratory factor analysis also showed similarity to the original scale except item 12 (able to forgive others), which was loaded in both the EX and RO components (0.813 and 0.544, respectively). Older patients had a better relationship with themselves and a lower level of existential fulfilment than the younger group. Patients who tried to find comfort in their religion or spiritual faith, actively performed religious rituals, and had affiliations with religious or spiritual communities showed significantly higher global SWB. ConclusionThe Bengali version of the EORTC QLQ-SWB32 is a reliable and valid tool for measuring the spiritual wellbeing of advanced cancer patients receiving palliative care.