The earthquake-induced permanent ground displacement constitutes a major hazard to the integrity of buried pipelines. A three-dimensional finite element model of cross-fault ductile iron pipeline is employed to analyze its mechanical response and failure modes under reverse and normal dip slip faults. A special emphasis is placed on the effect of the relative positions of the fault plane and the joint. The joint deformation of the ductile iron pipe subjected to dip-slip faults is found to be more pronounced compared to the strain response of the pipe itself, with failure damage most likely to occur at the joint. The relative position between the fault plane and joint does not change the force distribution on the pipeline joint but influences the failure location; the most severe seismic response occurs when the fault plane intersects the pipeline joint directly. The ductile iron pipeline is more likely to fail under reverse fault when angle between the pipeline and fault is 60° or 90°.