This study focuses on Livelihood Capital Index (LCI) as a useful tool in assessing the livelihood assets of rubber-based agroforestry farm households. It evaluates systematically all the livelihood capitals of rubber agroforestry farm households through developing an LCI. A total of 10 livelihood assets variables were broadly classified into five livelihood capital indicators namely; human, financial, physical, natural, and social. Data collected from 220 farm households through a questionnaire survey were normalized to construct five livelihood capital indicators and LCI. The appropriate weights for the livelihood capital indicators were assigned based on the principal component analysis (PCA). The average composite LCI was 0.49 for rubber-based agroforestry farm households and the human capital corresponds to the highest livelihood assets indicator (0.15) followed by financial (0.14), social (0.11), physical (0.05), and natural (0.05). The highest average LCI was reported by the rubber-based groundnut practice (0.54) followed by rubber-based cattle (0.53), cocoa (0.51), passion fruit (0.51), pepper (0.49), maize (0.49), and banana (0.48). Except for physical capital, it also indicates a statistically significant difference in livelihood capital indicators among the rubber agroforestry farmers and other income earners. A significant difference exists in the livelihood capital indicators except for human capital among the Divisional Secretariat. The outcome of this study suggests that the use of LCI is a more analytically rigorous comprehensive tool that can assess the livelihood of rubber agroforestry farmers and enable them to be improved their livelihood assets.