A tissue ablation device includes a catheter shaft having an antenna lumen, an impedance-matched microwave antenna carried in the antenna lumen of the catheter shaft, at least one cooling lumen in the catheter shaft around the antenna lumen for circulation of cooling fluid, and a microwave generator operatively coupled to the antenna for energizing the antenna to create a lesion in the targeted tissue around the catheter shaft having a controlled location and size. In an exemplary embodiment, a tip is attached to an end of the catheter shaft for penetrating the tissue targeted for treatment. The device is effective for laparascopic or percutaneous procedures to treat tissues such as the kidney.