Small Island Developing States (SIDS) face unique economic vulnerabilities due to their small size, insularity, remoteness, and susceptibility to natural disasters. These factors make their economies highly vulnerable to external forces, often masking their true economic condition through high GDP or GNP per capita figures. This paper discusses the major economic vulnerabilities of SIDS and attempts to quantify them using an index. It also constructs a composite vulnerability index to measure the lack of economic resilience in SIDS. The idea of constructing a vulnerability index emerged from discussions in international forums, particularly within the United Nations. The index aims to measure the structural and institutional weaknesses of SIDS rather than poverty. It is not intended as a measure of poverty but as a tool to highlight the lack of resilience of SIDS to external forces. The paper outlines the special economic disadvantages of SIDS, including limited natural resources, small domestic markets, dependence on a narrow range of exports, limited ability to influence domestic prices, and difficulties in exploiting economies of scale. Insularity and remoteness increase transport and communication costs, while vulnerability to natural disasters and environmental fragility further exacerbate these challenges. Additionally, SIDS often depend on foreign sources of finance and face demographic changes. The vulnerability index is constructed using three main variables: exposure to foreign economic conditions, insularity and remoteness, and proneness to natural disasters. These variables are standardized and weighted to create a composite index. The index is not correlated with GDP per capita, indicating that economic vulnerability is not necessarily linked to economic performance. The vulnerability index highlights that SIDS tend to have higher vulnerability scores than other countries. Despite some SIDS having high GDP per capita and Human Development Index scores, their economies are often fragile. The paper also suggests that the vulnerability index can help draw attention to the economic vulnerabilities of SIDS and provide a single-value measure of vulnerability for donor countries and organizations. The study concludes that SIDS are particularly vulnerable to external forces and require international support to mitigate these vulnerabilities. The index, while not perfect, provides a useful tool for assessing the economic resilience of SIDS and highlights the need for targeted policies and international cooperation.Small Island Developing States (SIDS) face unique economic vulnerabilities due to their small size, insularity, remoteness, and susceptibility to natural disasters. These factors make their economies highly vulnerable to external forces, often masking their true economic condition through high GDP or GNP per capita figures. This paper discusses the major economic vulnerabilities of SIDS and attempts to quantify them using an index. It also constructs a composite vulnerability index to measure the lack of economic resilience in SIDS. The idea of constructing a vulnerability index emerged from discussions in international forums, particularly within the United Nations. The index aims to measure the structural and institutional weaknesses of SIDS rather than poverty. It is not intended as a measure of poverty but as a tool to highlight the lack of resilience of SIDS to external forces. The paper outlines the special economic disadvantages of SIDS, including limited natural resources, small domestic markets, dependence on a narrow range of exports, limited ability to influence domestic prices, and difficulties in exploiting economies of scale. Insularity and remoteness increase transport and communication costs, while vulnerability to natural disasters and environmental fragility further exacerbate these challenges. Additionally, SIDS often depend on foreign sources of finance and face demographic changes. The vulnerability index is constructed using three main variables: exposure to foreign economic conditions, insularity and remoteness, and proneness to natural disasters. These variables are standardized and weighted to create a composite index. The index is not correlated with GDP per capita, indicating that economic vulnerability is not necessarily linked to economic performance. The vulnerability index highlights that SIDS tend to have higher vulnerability scores than other countries. Despite some SIDS having high GDP per capita and Human Development Index scores, their economies are often fragile. The paper also suggests that the vulnerability index can help draw attention to the economic vulnerabilities of SIDS and provide a single-value measure of vulnerability for donor countries and organizations. The study concludes that SIDS are particularly vulnerable to external forces and require international support to mitigate these vulnerabilities. The index, while not perfect, provides a useful tool for assessing the economic resilience of SIDS and highlights the need for targeted policies and international cooperation.