Women with early-stage breast cancer have an excellent prognosis with current therapy, but could presumably be treated less invasively, without the need for surgery. The primary goal of this meta-analysis was to examine whether thermal ablation is an effective method to treat early-stage breast cancer. Studies reporting on complete ablation rate after thermal ablation as a treatment of small breast cancers (≤ 2 cm) were included. Methodologic quality of included studies was assessed using MINORS criteria. Complete ablation rates are given as proportions, and meta-regression and subgroup analyses were performed. The overall complete ablation rate in 1266 patients was 86% and was highest after radiofrequency ablation (RFA) (92%). Local recurrence rates varied from 0% to 3%, with a median follow-up of 15 to 61 months. Overall, complication rates were low (5%-18% across techniques) and were highest after high-intensity focused ultrasound ablation and lowest after cryoablation. Cosmetic outcome was good to excellent in at least 85% of patients but was reported infrequently and long-term results of cosmetic outcome after thermal ablation and radiotherapy are still lacking. Thermal ablation techniques treating early-stage breast cancer (≤ 2 cm) are safe and effective based on complete ablation rate and short-term local recurrence rates. Especially, RFA, microwave ablation, and cryoablation are promising techniques as an alternative to surgical resection without jeopardizing current treatment effectiveness or safety. Owing to great heterogeneity in the included studies, a formal recommendation on the best technique is not possible. These findings warrant the design of large randomized controlled trials comparing thermal ablation and breast-conserving surgery in the treatment of T1 breast cancer.