Prospectively, in 15 children the association of acute transverse myelitis with Campylobacter jejuni infection and antiganglioside antibodies was studied. The clinical profile, radiological findings, and treatment outcome in these children were analyzed. Stool culture and serology for Campylobacter jejuni and antiganglioside antibodies were tested. In all, 15 age- and sex-matched healthy controls were tested for evidence of Campylobacter jejuni infection and antiganglioside antibodies. Anti-GM1 antiganglioside immunoglobulin G antibodies were found in 46% of patients with acute transverse myelitis versus 6.6% of controls (P = .035). Evidence of Campylobacter jejuni infection was absent in both the groups. The magnetic resonance imaging revealed longitudinally extensive lesions in majority. All children underwent intravenous high-dose corticosteroid treatment. At 1-year follow-up, 8 children had recovered completely, whereas 3 were nonambulatory. Bladder disturbances persisted in 7. The significance of these findings and the possible role antiganglioside antibodies may play in acute transverse myelitis pathophysiology is discussed.