Retrofitting is the strengthening of existing structures to enable them in carrying increased external loads. The need for retrofitting arises due to change in utility, expansion, damages due to accidents and environmental conditions. This paper presents an investigation of flexural behavior of plain cement concrete (PCC) beam retrofitted with ultrahigh strength concrete (UHSC) overlay. The proposed study consists of applying UHSC as a strengthening material on the bottom surface of the plain cement concrete beam in order to increase its stiffness and flexural strength. The beam of size 150 mm × 150 mm × 650 mm is tested for the failure load using M25 grade of concrete. Experiments were carried out under displacement controlled loading method. © 2017 Elsevier B.V., All rights reserved.