BACKGROUND: Neural tube defects (NTDs) are common congenital anomalies. Their aetiology is complex, with both genetic and environmental factors implicated. The present study was performed to analyse the birth prevalence of NTD in Switzerland from 2001 to 2007 and to identify possible risk factors. METHODS: Diagnosed cases of NTD in all paediatric units in Switzerland and four prenatal centres were reported to the Swiss Paediatric Surveillance Unit from January 2001 to December 2007. Patient, mother, and NTD characteristics were assessed prospectively with a questionnaire. RESULTS: Data of 140 newborns and foetuses with NTD were studied. The major group suffered from myelomeningocele (70%), followed by anencephaly (16%) and encephalocele (14%). The prevalence of NTD in live born children between 2001 and 2007 was 0.13 per thousand, corresponding to 9-10 affected newborns each year. About the same number of pregnancies was terminated annually. Correct periconceptual folic acid supplementation was taken by 5% of the women. Remarkably, 39% of the women with an affected pregnancy were not Swiss citizens - almost twice the proportion of foreigners living in Switzerland. CONCLUSIONS: NTDs remain a frequent problem in Switzerland. Although correct periconceptual folic acid supplementation is effective in reducing the prevalence of NTD, women still do not follow these recommendations. Possible reasons are lack of awareness and communication problems. Consequently, only a public health policy that includes folic acid fortification of food is likely to result in significant prevention of NTD.