This chapter gives an overview of causes and effects of damage due to low and medium velocity impact. Typical features of impact damage are described, with focus on tape prepreg laminates. The relation between impact response and impactor/plate mass ratio is explained and appropriate analytical response models outlined. Experimental observations of the behaviour of impact damage under load and its effect on strength and buckling are described. A brief discussion is also provided on the application of computational methods to impact on composites, and issues needing attention highlighted. The chapter is concluded with a discussion on future trends and advice for further information.