Purpose: This study aims to examine the behavioural and socio-cultural factors influencing the adoption and continued usage of Swachh Bharat Mission (SBM) sanitation facilities among tribal households in the Nilgiris district of Tamil Nadu. By integrating the Unified Theory of Acceptance and Use of Technology (UTAUT) and the Theory of Planned Behaviour (TPB), the research seeks to understand how awareness, social influence, perceived behavioural control, facilitating conditions, and behavioural intentions shape sanitation usage, attitudes, and perceived importance in tribal communities.

Methods: A descriptive research design was used to analyse sanitation behaviour among the tribal population in selected Nilgiris villages. Data were collected from 211 tribal respondents through a structured five-point Likert scale questionnaire administered via face-to-face interactions. Structural Equation Modelling (SEM) was employed to test the hypothesised relationships among key constructs from UTAUT and TPB. Model fitness was validated through CFA and SEM fit indices. Ethical guidelines for research within indigenous communities were followed, ensuring informed consent, confidentiality, and cultural sensitivity.

Findings: The results revealed that all proposed hypotheses were supported. Awareness, social influence, perceived behavioural control, and facilitating conditions significantly and positively influenced behavioural intention toward SBM adoption. Behavioural intention strongly predicted actual usage of sanitation facilities, while usage practices positively shaped both attitude towards SBM and the perceived importance of sanitation. Usage practices emerged as the strongest driver of perceived importance, emphasising the role of experiential learning in sustaining sanitation behaviour among tribal households.

Originality/Value: This study is among the first to integrate UTAUT and TPB in the context of sanitation behaviour within a tribal setting. While previous studies have focused on infrastructure or awareness components of SBM, this research offers a holistic behavioural perspective that combines individual beliefs, social norms, and structural support. The findings contribute theoretical value by extending technology-based behavioural models into a public health and rural sanitation domain. Practically, the study provides culturally grounded insights to guide policymakers, NGOs, and community organisations in designing more effective, tribal-sensitive sanitation interventions that go beyond toilet construction to foster long-term behavioural change