Using Meta-analysis to compare diagnostic value of contrast transcranial Doppler (c-TCD) and contrast transthoracic echocardiography (c-TTE) in right-to-left shunt (RLS) of patients with patent foramen ovale (PFO). Methods: Relevant literature from PubMed, Web of Science, Embase, Cochrane Library, CNKI, VIP, WanFang Data, and CBM from databases built until July 3, 2021 were retrieved. Statistical software Stata 15.1 and RevMan5.0 were used for statistical analysis. Results: A total of 766 articles were retrieved and 38 were included. Meta-analysis results showed the overall sensitivity of c-TCD (0.96, 95%CI 0.93～0.98) was higher than that of c-TTE (0.91, 95%CI 0.82 ~ 0.96), and the difference was statistically significant (Z=2.664, P= 0.008). The overall specificity of c-TCD (0.93, 95%CI 0.86～0.97) was lower than that of c-TTE (0.95, 95%CI 0.90 ~ 0.97), but the difference was not statistically significant (Z=0.481, P=0.630). The diagnostic odds ratio of c-TCD (DOR=384, 95%CI 156～943) and c-TTE (DOR=180, 95%CI 78～415) showed no significant statistical difference (Z=0.674, P=0.441). The area under the sROC curve (AUC) of c-TCD was higher than that of c-TTE but showed no statistical difference (AUC=0.99, 95%CI 0.97～0.99 for c-TCD v.s. AUC=0.98, 95%CI 0.96～ 0.99 for c-TTE; Z=0.357, P=0.507). Conclusion: For the diagnosis of PFO-RLS, both c-TCD and c-TTE have high diagnostic value.