Objective To investigate the association between right-to-left shunt (RLS) and sudden sensorineural hearing loss (SSNHL) by using propensity score matching to control for confounding factors. Methods We retrospectively analyzed the clinical data of patients with SSNHL (SSNHL group) and hospitalized patients without SSNHL or cerebral infarction (control group) admitted to the Department of Hyperbaric Oxygen, Sichuan Provincial People’s Hospital between January 2022 and May 2025. All subjects underwent contrast transthoracic echocardiography to assess RLS status. According to a 1:1 ratio, the age, gender, and comorbidities of the two groups were matched using propensity score matching, in order to balance baseline characteristics. A multivariate logistic regression model was used to quantify the strength of the association between RLS and SSNHL. Results A total of 335 subjects were included. Among them, there were 189 cases in the SSNHL group and 146 cases in the control group. Before matching, there were significant differences between the two groups in age, other comorbidities, and RLS positivity rate (P<0.05), except for gender and coronary heart disease (P＞0.05). After matching, 97 pairs of patients with balanced and comparable baseline characteristics were selected. After matching, the prevalence of RLS in the SSNHL group was significantly higher than that in the control group (57.7% vs. 34.0%; χ2=10.982, P＜0.001). The results of multiple logistic regression analysis showed that RLS was associated with SSNHL. Conclusions The association between RLS and SSNHL suggests that clinicians should prioritize RLS screening in patients with SSNHL to assess potential cardio-cerebrovascular risks