System for increasing a target zone for electrical ablation includes a treatment control module executable a processor. The control module directs a pulse generator to apply pre-conditioning pulses to subject tissue cells in a pre-conditioning zone electroporation, the pre-conditioning zone being smaller than a target ablation zone. After the pre-conditioning pulses have been applied, the control module directs the pulse generator to apply treatment pulses to electrically ablate the tissue cells in the target ablation zone. The pre-conditioning pulses cause the pre-conditioning zone to have a much higher conductivity so that the zone acts as a larger electrode area when the treatment pulses are applied, which result in a much larger target ablation zone than otherwise possible.