To evaluate the safety and outcomes using a 915-MHz synchronous wave microwave ablation system in renal ablation of T1A and T1B tumors. The study was IRB approved and HIPAA compliant. Renal ablation cases were retrospectively reviewed from July 2013 to August 2017. Microwave ablation cases were evaluated by imaging and chart review. Patient demographics, imaging follow-up, and complications were reviewed. Microwave ablation was performed using a 915-MHz ablation system. Number of probes, wattage, and ablation time were determined by the interventional radiologist. If diagnosis was unknown, biopsy was performed at the time of the ablation. 88 ablations were performed at a single institution with 58 patients undergoing microwave ablation. Follow up was at least 3 months with average follow-up of 9 months ± 7.8 months. Average lesion size was 2.3 ± 0.95 × 2.0 ± 0.77 × 2.3 ± 0.97 cm. The average probes placed was 1.93 ± 0.62 with average ablation energy of 1137 ± 493. Biopsy showed 30 renal cell carcinomas, 6 oncocytomas, 5 angiomyolipomas, 13 non-diagnostic biopsies, and 4 other pathologies. Two patients had residual tumor noted on follow-up CT, both with T1B tumors, which were subsequently completely treated with follow-up ablation. There were one minor and two major complications following ablation: one pneumothorax from probe placement not requiring chest tube, one renal bleed requiring transfusion, and one acute kidney injury which improved with conservative management. Ablation has been reported using 2450-MHz system in the kidney. This series represents one of the larger short-term follow-up studies for 915 MHz. 915-MHz ablation is safe and effective for renal ablation with low complication rates.