This paper deals with an analysis of a low energy impact on unidirectional S-Glass/Polyester composite plate. A set of low energy impact tests was carried out on composite plates in a bending configuration. The impact loads were applied using drop-mass tower. The mechanical responses, such as impact force, bending, energy dissipation and damage are highlighted and analysed. A reliable finite element model is developed to calculate, and then to compare to experiments, all mechanical responses. An analysis of the stress state and damaged surfaces induced by the impact is performed based on the Hashin's damage criterion. The effect of the drop height on the degradation of the composite material is highlighted, particularly the extent of the damaged area. It is shown that the maximum bending and the maximum impact force follow linear evolution with respect to the drop height. Also, the model reproduced well experimental observations, such as damage generated in the inter-plies, the damaged zone extent and other mechanical responses. A parametric study was performed to highlight the effect of relevant design parameters on the mechanical response of the composite laminate to the impact loading.