Stranded tar along the Brittany coast and four test sites in Indonesia (Jakarta Bay, Malacca and Makassar Straits, Central South Java) were surveyed in 1982 in order to quantify and identify the possible origin of oil pollutants. The estimation of tar pollution was determined by a statistical methodology based on a stratified random sampling. Western Brittany and Jakarta Bay must be regarded among the areas most vulnerable to chronic oil pollution with respectively gross weight values of 76.9 ±115.6g/m and 812.7±219g/m, comparable to those of other coasts along major tanker routes such as Kuwait or Bermuda. The levels on the other sampled sites were relatively low in spite of such dense maritime traffic as in Malacca straits (15.4 ±5.4 g/m) or near the mouth of La Loire (12.2±15.9 g/m and less than 0.5 g/m in the Bay of Saint-Brieuc). Hydrocarbons in tar samples were examined by liquid and gas chromatography for a classification in crude oil residues, sludge residues and fuel oil. A multimethod approach combining GC, IR, SFUV and sulfur content was used for a characterization of oil extracts and their tentative matching with the physico-chemical parameters of some reference oils.