Guillain-Barré syndrome (GBS) is a rare but serious complication of infectious intestinal disease due to Campylobacter jejuni. To date, estimates of the burden of C. jejuni-associated GBS have been based on limited data regarding the proportion of GBS attributable to this pathogen. In this paper, we combine data obtained from Sweden and a large study of infectious intestinal disease with routine and surveillance data from England to estimate the number and proportion of GBS cases attributable to C. jejuni. We estimate that, between 1 April 2000 and 31 March 2001, symptomatic C. jejuni infection was responsible for 157 cases of GBS, constituting approximately 15% of all GBS cases in England.