Objective This study aimed to investigate serum matrix metalloproteinase (MMP)-2 and MMP-9 levels in patients with papillary thyroid carcinoma (PTC). Methods Forty-one patients with PTC undergoing ultrasound-guided radiofrequency ablation (RFA) and 56 controls were included. Serum MMP-2 and MMP-9 levels were determined by enzyme-linked immunosorbent assay before and after surgery. Potential affecting factors were evaluated by logistic regression analysis. Results Serum MMP-2 and MMP-9 levels were significantly higher in PTC patients compared with controls, and decreased significantly after surgery. According to receiver operating characteristic curve analysis, diagnostic values for preoperative serum MMP-2 and MMP-9 levels were 82.4% and 86.6%. There was no contrast-agent perfusion in the ablation zone in 88.5% of lesions, and enhancement within or at the lesion edge in 11.4%. The volume reduction at 3 months’ follow-up was >40%. Age, microcalcification, irregular shape, and lesion diameter and number were influencing factors for PTC. Age, and lesion diameter and number were independent risk factors, while calcification and morphology were protective factors. Conclusion Serum MMP-2 and MMP-9 levels have important clinical values for the diagnosis and treatment of PTC by RFA. Preoperative serum MMP-2 and MMP-9 levels, combined with other affecting factors, contribute to disease prognosis.