Abstract European work on the application of biotechnology to processing various coals is reviewed and set within a wider context. Both U.S. and European work are discussed. In connection with work on microbial desulphurisation, European effort, particularly that centred on Delft University in the Netherlands, has concentrated on looking towards practical plant designs based on kinetic reaction data obtained in the laboratory. The question of desulphurisation looks rather different from a European (and world) perspective, compared with the situation in the U.S. There are, for example, several countries with high sulphur, low rank coals, where a higher proportion of the sulphur is present in organic form. While the work on pyrite removal has been well documented and has been replicated by different workers, that on organic sulphur removal is at a much earlier stage. In the U.K., work is going on to enhance the physical separation processes currently used in coal cleaning, using micro-organisms to alter the surface properties of various particles during flotation. This approach has the possibility of relatively short-term application and low capital cost Some fundamental studies looking for organisms to attack and degrade the coal molecule, particularly in the F.R.G., have been based on bituminous coal. This contrasts with U.S. work which has met with some success with lignites and weathered lignite in the form of leonardite. The use of biotechnology in connection with coal must be looked at principally as a potential long-term development. The inherent problems associated with the nature of coal must be recognised but research work is already demonstrating possibilities that even 5 or 10 years ago would have been discounted. With advances in analytical techniques, one of the first benefits to be gained may well be a better knowledge and understanding of coal structure from looking at its degradation products.