Objective: Amyloid A is an acute phase protein, which can be released into blood to activate immune cells and induce cytokines, and is associated with a variety of inflammatory conditions. The present study was designed to investigate the relationship between serum amyloid A levels and glucocorticoid (GC) sensitivity in patients with sudden sensorineural hearing loss (SSNHL). Methods: A total of 117 SSNHL patients were collected and divided into GC-sensitive group and GC-resistance group, with 90 healthy individuals with matched age and gender served as the control group. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum amyloid A levels. Results: SSNHL patients had significantly higher serum amyloid A levels than healthy controls, among SSNHL patients, GC-resistant group had higher serum amyloid A levels than GC-sensitive group. The cut-off value of amyloid A was 358.5 pg/mL (sensitivity=86.8%; specificity=81%), which can identify GC-resistant subjects in SSNHL patients. Among all patients, serum amyloid A level showed a significant positive relationship with serum malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hs-CRP) and interleukin-1β (IL-1β). The in vitro proliferation inhibition test showed that inhibition rate of peripheral blood mononuclear cells (PBMCs) by dexamethasone (Dex) showed negative correlation with serum amyloid A level. Multivariate logistic regression analysis showed that serum amyloid A, as well as MDA, TNF-α, IL-1β and GC inhibition, were independent risk predictors of GC resistance. Conclusions: Serum amyloid A level is elevated in SSNHL patients with glucocorticoid resistant, and is associated with enhanced oxidative stress and proinflammatory cytokines production.