Preceding infections and anti-ganglioside antibodies were assessed among 80 Guillain-Barré syndrome (GBS) patients and 125 controls. Previous infections were more frequent among GBS patients than among controls (p <0.0001), and had a significant association with axonal subtype compared with acute inflammatory demyelinating polyneuropathy (AIDP) (29/46 vs. 10/34 patients; p <0.05). Campylobacter jejuni (26%) was the most common preceding infection among GBS patients, followed by Mycoplasma pneumoniae (15%). Anti-ganglioside antibodies were detected more frequently among GBS patients than among controls (65/80 vs. 13/125; p <0.001), and a higher proportion of axonal cases had these antibodies than did AIDP patients (43/46 vs. 22/34; p <0.01).