Syntactic foams are polymer composites obtained by dispersing hollow spheres in a matrix. They have excellent properties such as low density, high specific strength, low moisture absorption, lower thermal coefficient of expansion, and in some case radar or sonar transparency for use in Stealth technology. One of their biggest advantages is the fact that they can be tailored to have the properties necessary for a specific product. Syntactic foams uses include: marine applications, aerospace, ground vehicles, and sports applications (snow skis and soccer balls). In fact, they can be used for anything that needs a high strength material. Update on Syntactic Foams will be of interest to all those who produce polymer products that need very high strength due to the adverse conditions that they are used in, as well as manufacturers of raw materials used in these products. This Update gives the reader a good insight into the properties, manufacture and uses of syntactic foams, including: * The basics of syntactic foams including the types of microballoons used, foam structure, methods of synthesis and the properties. * Syntactic foams based on different types of resin systems such as epoxy, phenolics, cyanate ester and so on. * Recent developments in the field such as fibre reinforcement, nanoclay reinforcement, functionally grading of foams, rubberisation, syntactic foam core sandwich composites and cement-based syntactic foams. * Appplications of syntactic foams.