Wave transformation describes the propagation of waves and water surface displacement from offshore to onshore. The magnitude of wave generation and wave set-up are dependent on a number of factors such as wind speed, water depth and tide level. This paper has investigated the characteristics of wave transformation in Manila bay along Roxas boulevard during extreme conditions specifically on typhoon events. Records of typhoon that struck Manila bay area for the past 40 years were used to generate the wave height and water displacement profiles through a numerical simulation model developed by Kraus and Larson (1991). Parameters such as water depth, wind speed and tide level were the input data in the simulation. Six transects were established up to a depth of 20m to describe the cross-shore profile fronted by breakwater structure and open sea. Results show that the wave height and water surface displacement are significantly higher in transects which are not exposed to any breakwater structure. A wave generated by a typhoon with a wind speed of 42 mps similar to that of typhoon Narsing in 1973 would definitely overtop the existing seawall situated along Roxas boulevard.