This study aimed to evaluate the efficacy and safety of ultrasound (US)-guided minimally invasive treatment in patients with parathyroid lesions. Materials and Methods: This study included 27 patients who had undergone US-guided radiofrequency ablation (RFA) or ethanol ablation (EA) for parathyroid lesions between January 2010 and 2018. RFA was performed in 19 patients with primary hyperparathyroidism (PHPT, n = 11) or secondary hyperparathyroidism (SHPT, n = 8), and EA was performed in eight patients with symptomatic nonfunctioning parathyroid cysts (SNPCs). Nodule size, volume, serum parathyroid hormone (PTH) and calcium levels were recorded before and after treatment. Complications were evaluated during and after treatment. Results: In patients with PHPT, significant reductions in size and volume were noted after RFA at 6-and 12-month follow-up (all, p < 0.05). Seven nodules nearly completely disappeared (residual volume < 0.1 mL); serum PTH and calcium levels were reduced to normal ranges (7/11, 63.6%). Four patients experienced partial reductions of serum PTH and calcium levels (4/11, 36.4%). In patients with SHPT, three experienced therapeutic response of serum PTH (3/8, 37.5%), while five showed persistent hyperparathyroidism (5/8, 62.5%) within 6 months after RFA. In patients with SNPCs, EA resulted in significant reductions in cyst size and volume (all, p < 0.05) at the last follow-up. A total of four complications (two transient hypocalcemia [RFA], one permanent [RFA], and one transient [EA] hoarseness) were observed. Conclusion: Minimally invasive treatments, such as RFA and EA, may serve as therapeutic alternatives for patients with PHPT or SNPCs; they may have limited usefulness in patients with SHPT.