In this study, undrained capacity of suction piles subjected to moment loading is examined using three-dimensional finite element analysis. The model was initially validated against well-established results in literature. The model was then used to investigate the effect of moment loading on vertical and torsional capacity by performing a sensitivity analysis by varying soil heterogeneity and suction pile geometry. The parametric study was carried out for suction piles with length to diameter ratios (L/D) varying from 1 to 7 embedded in soils with constant and linearly varying shear strength. The failure envelopes presented provide a better understanding and a simpler and quicker design method that can be readily used for the design of suction piles.