We performed a case-control study to investigate the association between Campylobacter jejuni (CJ) infection and Guillain-Barr| syndrome (GBS) or Miller-Fisher syndrome. We compared 60 cases with 109 hospital controls matched for age, gender, hospital and geographical location. To diagnose the CJ infection, we considered the association between serologic positivity for CJ and a previous diarrheal illness within 3 months of inclusion in the study. Fifteen percent of cases versus 5% of hospital controls had CJ infection (p < 0.003, OR = 3.96, 95% CI: 1.0817.85). However, CJ infection was related to GBS only if it occurred during the previous month (p< 0.001, OR = 7.29, 95% CI: 1.4371.28). No statistical differences were found between the cases who were positive for CJ infection and those who were negative for CJ infection when studied by stepwise multivariate logistic regression for age, gender, clinical and electrophysiological features and outcome. Recent CJ infection may be a risk factor for GBS.