Purpose: Computed tomography (CT) guidance and general anesthesia have recently been recommended as the approach of choice for percutaneous ablation of small renal cell carcinoma (RCC), whereas ultrasound (US) guidance and conscious sedation have been tagged as inadequate. Aim of the study was to assess the safety and effectiveness of percutaneous thermal ablation of small RCC under ultrasound (US)-guidance and conscious sedation. Methods: The records of 74 patients with small RCC (≤5 cm), who underwent US-guided thermal ablation under conscious sedation were retrospectively reviewed. Conscious sedation was usually induced by means of intravenous bolus of midazolam 50-100 µg/kg plus continuous infusion of a 25 µg/mL solution of remifentanil at a rate of 0.05 µg/kg/min. Technical success, technical efficacy, local tumor progression (LTP), primary and secondary efficacy rates, complication rate, and 1-, 3-, and 5-year survival rates were analyzed. Results: No procedure needed to be converted to general anesthesia, and all tumors were treated according to the protocol, with a technical success of 100%. One patient died after surgical intervention for bowel perforation and other 2 patients experienced grade 3 complications. Mortality rate and major complication rate were 1.3% and 2.7%, respectively. One-month technical efficacy was 100%. LTP was observed in 4/74 patients, with a primary efficacy rate of 94.6%. Two of them underwent successful thermal ablation and secondary efficacy rate was, therefore, 97.3%. The median follow-up was 38 months (range 1-130 months). No patient died for tumor progression. 1-, 3-, and 5-year survival rates were 94%, 80.5%, and 60%, respectively. Conclusion: US guidance and conscious sedation remain valid alternatives to CT guidance and general anesthesia for the percutaneous ablation of small RCC.