Clinicians increasingly perform balloon dilation of the Eustachian tube (BDET) to treat obstructive Eustachian tube dysfunction (OETD) refractory to medical management. Reported complications have been limited and include patulous Eustachian tube dysfunction (PETD). This multicenter study investigates the incidence of PETD and associated factors. Consecutive patients at three academic centers undergoing BDET (January 2014-November 2019) for OETD refractory to medical therapy were included. PETD was diagnosed by patient-reported symptoms of autophony of voice and/or breathing. Associated factors studied include age, sex, comorbidities, balloon size, duration of inflation, repeat BDET, and adjunctive procedures. BDET procedures (n = 295 Eustachian tubes) were performed on 182 patients. Mean age was 38.4 years (SD 21.0; range 7-78) and 41.2% were female. Twenty cases of PETD (6.8% of procedures; 9.3% of patients) occurred following BDET. Risk of PETD did not vary by institution, comorbidities, or adjunctive procedure. Age ≤18 years (adjusted risk ratio [RR] = 3.26; 95% confidence interval [CI]: 1.24, 8.54; p = 0.02), repeat BDET (RR = 3.26; 95% CI: 2.15, 4.96; p < 0.001), and severe preoperative Eustachian tube inflammation (RR = 2.83; 95% CI: 1.10, 7.28; p = 0.03) were associated with increased risk of developing PETD in the multivariable model. Most symptoms were reported as mild or intermittent. BDET caused PETD symptoms in approximately 7% of dilated Eustachian tubes in this study with increased risk for younger patients and those with severe inflammation or undergoing repeat dilations. Although most cases were self-limited, symptoms can persist. Awareness of risk factors may aid clinicians in limiting this complication. 4 Laryngoscope, 133:3152-3157, 2023.