In this study, the seismic vulnerability of a pile-supported wharf is assessed. Due to common lack of empirical data, the analytical fragility curves are developed using the results of the dynamic analysis of wharf subjected to the different time histories. Fragility curves are developed considering three engineering demand parameters, including displacement ductility factor (μd), differential settlement between deck and behind land and normalised residual horizontal displacement (NRHD). A sensitivity analysis using both the first-order second-moment method and the tornado diagram analysis is then carried out to evaluate the effects of uncertainties associated with geotechnical parameters in the seismic performance of the wharf. Adopted fragility curves are useful to seismic risk assessment. They can also be used to optimise wharf-retrofit methods. The results of sensitivity analysis demonstrate that uncertainties associated with the permeability of hydraulic placed sand fill contribute most to the variance of both NRHD and μd. While in the case of differential settlement, the friction angle of rock fill contributes most to the variance.