The volume decribes the complexes of gallium with water, alcohols, aldehydes, ketones, quinones, ethers, O-heterocycles, carboxylic acids, ammine, amines, and N-heterocycles containing one nitrogen atom in the ring. Many of these complexes are of fundamental importance in the industrial and analytical chemistry of gallium. A large number of publications describe the separation and quantification of gallium in the form of coordination compounds. This often involves extended solvent extraction studies. The present volume offers a state-of-the-art description of the complexes formed in both analytical procedures and industrial processes and will help the reader understand the fundamental chemistry involved. Certain gallium complexes are used in pharmacology. Complexes with the radionucleide 67Ga were tested to diagnose to locate malignant tumors. A widely used complex is 67gallium(III) citrate. This and other complexes are described in this volume were also tested as anticancer chemotherapeutic agents. Despite the aforementioned use of gallium complexes in clinical and industrial chemistry, often only vague ideas exist about the precise composition of the complexes, even for isolated and stable compounds. The coordination chemistry of gallium requires aditional chemical and physicochemical studies using modern techniques. Therefore this new volume of the Gmelin Handbook will certainly inspire new research to fill the gaps in the chemistry of the important element gallium.