This book serves as a concise guide to essential topics in Transition Metal Organometallic Chemistry for senior undergraduate and graduate students; it blends qualitative theoretical approach with experimental description of the facts. Its content emphasizes on the orbital description of M-L bonds; the electronic structures of the main types of organometallic complexes (ML2 to ML6); main types of organometallic reactions; organometallic compound synthesis, analytical characterization and the reactivity and lastly the applications of transition metals in homogeneous catalysis.