This study examines the behavior of buried pipelines subjected to external pressure from surrounding soil and internal pressure from carried gas. A 3D finite element model of the pipeline was created in ABAQUS. The pipeline was analyzed under external pressure only and under both external and internal pressures. Two parameters were used to determine onset of buckling: total energy and axial strain. For external pressure only, buckling began around 0.32 seconds as seen in fluctuating total energy and decreasing axial strain plots. For both pressures, buckling began around 0.44 seconds. The internal pressure delayed buckling compared to external pressure alone.