All materials produced from inorganic hydraulic cements are composites of one kind or another because of their multiphase nature. This paper briefly considers the relevance of composite principles in predicting the mechanical properties of hardened cement paste, mortar and concrete and then discusses recent developments towards enhancing these properties by the addition of polymers and more particularly fibres. Fibres derived from glass, polypropylene and cellulose with metal wire are currently being used as cement reinforcements. Important properties of some of these practical fibre reinforced cement and concrete (F.R.C.) materials are discussed with particular reference to the replacement of asbestos products. Some examples of recent innovations in the manufacture of F.R.C. materials are given together with projections for their future use.