The objective of this chapter is to investigate how prestress affects the low-velocity impact behaviour of flat and curved laminated composites. Most of the literature concentrated on low-velocity impact behaviour of laminated composite materials without any preloads. However, in real structures, low-velocity impacts are expected to occur during the life of the structure, which is subjected at least to the design load. In addition, curved laminates are extensively utilized in engineering applications. This article reviews the significance of preload, curvature and thickness parameters that influence impact response as regards the severity of damage, the damage tolerance and the structural integrity of laminated composites. More attention is needed in the design and maintenance of laminated composites under preload, especially for the curved structures, as they are further susceptible to low-velocity impact.