Composite materials, such as carbon-fibre-reinforced polymers, are increasingly being used in the fabrication of high-performance structures. Composite laminates often show considerable advantages of stiffness and strength over homogeneous materials, and this is particularly evident when these properties are considered on a unit weight basis. However, these advantages are counterbalanced by a lower impact-damage tolerance. An impact-induced damage in composite materials may significantly reduce the mechanical properties of composites leading to a sudden and unexpected failure of the component. Therefore structural health monitoring and damage detection in civil, mechanical and aerospace engineering constructions has become one of the most important keys in maintaining the integrity and safety of a structure. In the present paper a technique for damage detection which utilizes modal curvatures obtained from vibration analysis is proposed for the detection of internal defects arising as a result of low-velocity impacts on composite laminates.