BackgroundGrowing cancer incidence and its subsequent burden is a worldwide concern. Needs assessment for caregivers has recently received growing attention, as it identifies specific unmet needs. The remaining tools have been established within the healthcare context of Western countries and have been studied only in some Asian populations; it seems appropriate to develop needs assessment tools that apply to a wider ethnic and socio-cultural context. ObjectiveThis study planned to adapt and examine the psychometric properties of the CNAT-C for the Sri Lankan informal caregivers for wider applicability. DesignAn instrument development and cross-sectional validation study was conducted. SettingApeksha Hospital Maharagama, Sri Lanka (National Cancer Institute). ParticipantsA sample of 226 informal caregivers (ICs) providing palliative care for patients with advanced cancer was selected. MethodsA CNAT-C (41 items; seven factors) was incorporated and used after a cross-cultural adaptation following WHO guidelines after the permission and pilot test. ICs completed the socio-demographic and clinical details along with the validated Centre for Epidemiological Studies-Depression (CES-D), and the World Health Organization-Quality of Life-Brief (WHOQOL-BREF). Internal consistency and test-retest were used to check the reliability. Convergent and divergent validity of the Sinhala version of CNAT (S-CNAT) was confirmed using the CES-D scale and WHOQOL-BREF. Construct validity was evaluated using the exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). ResultsMost of the participants were female (60 %) and married (72 %), and the mean age was 41.78 (SD+14.54). Face and content validity were established during the cross-cultural adaptation. Cronbach's alpha was 0.903 for the overall S-CNAT and the test-retest reliability was 0.965. The S-CNAT was associated positively with the CES-D while negatively with the WHOQOL-BREF. Both EFA and CFA discovered a structure contained seven factors (35 items); domain named as healthcare staff/nurses’ support and information, physical/practical needs, medical officers’ support, psychological needs, social/family support, spiritual/religious support, and hospital facilities/service. ConclusionsThe Sinhala version of CNAT is shown to have adequate validity and reliability in assessing the comprehensive and multidimensional/unmet needs of informal caregivers of patients with advanced cancer (S-CNAT-ICs). It would be a helpful tool to determine the unmet needs of ICs and guide future interventions to meet those needs and enhance or maintain the quality of life for patients and their informal caregivers.