OBJECTIVES: We characterize occult lesion diagnosis rates after initial Bells palsy diagnoses. METHODS: A de-identified database of all facial palsy patients who presented to an extensive health care system across 22 years was created using Epic SlicerDicer. Among patients with Bells palsy diagnoses, we extracted demographic and any subsequent occult lesion diagnosis data across various clinical sites. Descriptive and multivariable regression analyses comparing patients with occult lesion diagnoses made at different time points were included. RESULTS: Among the total 3912 facial palsy patients, 2240 had Bells palsy diagnoses, of which 217 (9.7%) had subsequent lesion diagnoses at a median (IQR) of 12.3 (4.2, 23.8) months, consisting of cranial nerve neoplasms (62.2%), parotid gland neoplasms (34.1%), and cholesteatomas (3.7%). Although a large proportion of total lesions were diagnosed within the first 3 months (19.8%), 69.5% were diagnosed after 6 months. There were no demographic differences among patients diagnosed with different lesion types, but Asian patients were more likely to be diagnosed with occult lesions after 12 months after Bells palsy diagnosis compared with white patients (odds ratio = 6.2, p = 0.001). CONCLUSIONS: In one of the largest Bells palsy cohorts to date, we identified a 9.7% occult lesion diagnosis rate at a median of 12.3 months after Bells palsy diagnosis. These data underscore the importance of timely workup for occult lesions in cases of facial palsy with no signs of recovery after 3-4 months. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:911-918, 2024.