Mooring dolphins are generally supported on group of piles and these piles are subjected to significant lateral loads due to mooring pull of the berthing vessel and wind and wave action. In this investigation, the behaviour of pile groups under lateral load has been studied by conducting static load tests on instrumented model pile groups embedded in clayey soil, changing the spacing between piles, number of piles and the arrangement of piles in the group. The results indicated that the capacity of a pile group depends not only on the spacing of piles in the group but also on the arrangement of piles with reference to the direction of loading. For cyclic load application, the deflections are observed to stabilize after some cycles depending on the cyclic load level. The post cyclic behaviour of the piles has been explained in terms of the changes in the soil strength behaviour during cyclic loading.