Biological and Synthetic Polymer Networks contains 36 papers selected from the papers presented at NETWORKS 86, the 8th Polymer Networks Group Meeting. NETWORKS 86 was held in Elsinore, Denmark, on 31 August 5 September 1986. A total of nine invited main lectures and 68 contributed papers were presented at the meeting. A wide range of important biological and synthetic materials consist of three-dimensional polymer networks. The properties range from very stiff structural materials to extremely flexible rubbery materials and gels. Most polymer networks are permanent networks held together by covalent bonds. Such networks are insoluble but they may swell considerably in good solvents. Polymer networks held together by ionic bonds, hydrogen bonds or so-called entanglements are of a more temporary nature. At long times they exhibit a tendency to flow, and they are soluble in good solvents. The paper by Professor Walther Burchard and his co-workers, 'Covalent, Thermoreversible and Entangled Networks: An Attempt at Comparison', serves as a general introduction to polymer networks. The book contains both theoretical and experimental papers on the formation, characterisation and properties of polymer networks. Two topics were given special sessions at the meeting, namely Biological Networks and Swelling of Polymer Networks.