Background <p>Over 1.5 million Sri Lankans are employed overseas, predominantly as temporary migrant workers in the Middle East. Despite their substantial contribution to the national economy, empirical evidence on their reintegration experiences after return remains limited. This study aimed to develop and validate an Index of Reintegration (IR) to assess the reintegration status of workers who returned from the Middle East and are living in the Kurunegala District, Sri Lanka.</p> Methods <p>The IR was developed using a three-phase process: item development, scale development, and scale evaluation. Item development utilised deductive (literature review) and inductive (interviews with experts, returnees and their families) methods. A community-based survey among 650 returnee migrant workers in Kurunegala District collected data for factor analysis in the scale development phase. Developed scale was evaluated for its reliability and validity.</p> Results <p>Exploratory Factor Analysis revealed a 20-item IR with six factors, explaining approximately 60% of the total variance. Confirmatory Factor Analysis affirmed significant factor loading for all items to their respective factor and supported the goodness of fit for the six-factor model. The factors encompass Economic Self-Sufficiency, Family Reacceptance, Physical-Psychological Health, Social Stability, Support Networks, and Cultural Adaptation. Scale evaluation for reliability indicated Cronbach’s alpha values ≥ 0.7 for all components. The scale underwent validation for content validity and exhibited good construct validity.</p> Conclusions <p>The IR is a reliable and valid tool to assess the reintegration status of Sri Lankan workers who returned from Middle East. The scale has broad applications for research and practice. Further research across diverse migrant worker groups is recommended to enhance the scale’s generalisability and robustness.</p>