The latest developments in the immobilization of well-defined transition metal-based catalysts relevant for C-C and C-Si coupling reactions are summarized. In this context, both ruthenium- and molybdenum-based metathesis as well as hydrosylation catalysts are covered. Particular attention will be attributed to synthetic aspects of the novel immobilization techniques as well as comparisons between the catalytic activities of the immobilized catalysts and their parent homogeneous systems. Finally, the influence of the chemical nature of both the support and linker on catalysts characteristics will be discussed. (c) 2005 Elsevier B.V. All rights reserved.