Guillain-Barré syndrome (GBS) is an inflammatory disorder that may implicate proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha) in its pathogenesis. The association between TNF-alpha 308 G/A polymorphism and GBS largely remains unknown. The aim of this study was to investigate the association between TNF-alpha 308 G/A polymorphism and GBS in Chinese Han patients. TNF-alpha 308 G/A polymorphism in 150 GBS patients and 150 healthy controls were studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Patients with GBS had a significantly higher frequency of TNF-alpha 308AA genotype [odds ratio (OR) = 3.79, 95% confidence interval (CI) = 1.03, 13.94; P = 0.04] than controls. When stratified by the GBS subtype, there was a significantly higher frequency of TNF-alpha 308AA genotype in patients with AMAN (OR = 6.05, 95% CI = 1.45, 25.31; P = 0.01) and AMSAN (OR = 5.56, 95% CI = 1.18, 26.23; P = 0.03) than controls. There was no significant difference in the distribution of each genotype between patients with AIDP and the control group. These data indicated that TNF-alpha 308AA genotype was associated with a higher risk of GBS in Chinese population, especially to AMAN and AMSAN.