With increasing environmental legislation, the synthesis of catalysts that can be easily recovered, give high selectivity and produce low levels of waste is highly desirable. Immobilising an active species on a support material can ease the separation from a reaction, allowing the material to be used again. A constant goal for the selective oxidation of organic substrates is the design of new and improved heterogeneous catalysts. Recent highlights of research towards this goal are reviewed. (C) 2000 Elsevier Science B.V. All rights reserved.