This research develops an integrated environmental assessment tool for Lithuanian coastal area that takes due account of the major oil spill risks posed by the D-6 oil drilling platform, vessel traffic in the southeastern Baltic Sea, and operation of the Būtingė oil terminal. The goal of this paper is to present an environmental sensitivity index (ESI) mapping approach based on four specific indexes: coastal features (ESIC), socio–economic aspects (ESISE), biological (ESIB) and fishery resources (ESIF). The relevant methodology approach was selected. The core dataset is provided by GIS–based environmental atlas updated with other relevant GIS data of Lithuanian coastal resources. Four ESI maps were developed and an overall environmental sensitivity index (OESI) map produced. Results indicate that in the case of an oil spill, two areas need to be prioritized due to their biologic and socio–economic resources: the 25 km long shoreline between the settlements of Nida–Juodkrantė on the Curonian Spit (CS) and the mainland coast (MC) between the settlements Palanga and Šventoji.