Letal spina bifida continue to be frequent in Tunisia ; we report 88 cases of letal spina bifida : 1,05 per thousand births. This pathology was more frequent with women. The up letal spina bifida situated is predominant with female and the dow spina bifida situated is frequent with male. We hove noted an association with anencephalia (40 cases) and hydrocephaly (21 cases). Prevention is based on obstetric health care and hygieno dietetic advices to avoide alimentary deficit.