In the wider Caribbean region, Trinidad has been classified as a high risk area for oil spills by the Intergovernmental Marine Consultative Organization. Tn order to develop an oil spill environmental sensitivity index, the intertidal zones of fifteen representative coastal sites were monitored for physical and biological parameters during the dry and wet seasons. On a scale of 1-10, sheltered habitats with high productivity are the most sensitive to spilt oil with an index value of 10. Exposed habitats with low productivity are the least sensitive with a value of 1, The index applied to coastal habitats in Trinidad is as follows: mangrove swamps (10), coral-algal reefs (9), sheltered rocky coasts (8), sheltered tidal flats (7), mixed sand and gravel beaches (6), sheltered fine to medium-grained sand beaches (5), exposed rocky shores (4), exposed tidal flats (3), exposed medium to coarse-grained sand beaches (2) and eroding wavecut platforms (1). This study demonstrates an approach to effectively combine biological and physical parameters into a single environmental sensitivity index: to oil spills.