The potential of carbon and sulphur isotope ratios to group crude oils with respect to their origin was investigated. Sample selection was based on the actual crude oil imports to Germany. Analysed curde oils from Algeria, the Community of Independent States (CIS), Middle East, Nigeria, the North Sea and Venezuela make up over 86% of the German crude oil imports. The oil as received was deasphalted and the maltene fraction was separated by MPLC into saturated, aromatic and polar fractions. Due to overlapping areas, it is not possible to group the crude oils by their δ13C values alone. A complete grouping of the crude oils with respect to their origin can only be achieved by the combined use of δ13C and δ14S of crude oils, and isotope type-curves. In some cases isotope type-curves enable differentiation between different oil fields of the same geographical origin.