Wave transmission is one of the components resulted from interaction between incident wave and coastal structure. Factors influencing wave transmission include structure height, crest width and wave condition. This paper presents the analysis of wave transmission and dissipation capability of Interlocking Concrete Unit-V (ICU-V) under different wave conditions and structural parameters based on a 2-D physical model testing. The transmitted wave was reduced more than half of the incident wave when the relative crest height is greater than zero. Structural irregularity of ICU-V promotes breaking of wave on the breakwater crest and the sloping surface. The crest is less effective when the submergence depth greater than -0.20 m or the relative freeboard is greater than -0.286. Overall, ICU-V offers good ability for wave dissipation, which leads to promising performance in sheltering coastal area. © (2014) Trans Tech Publications, Switzerland.