This paper presents the trend of spina bifida and other neural tube defects in Oman after the nationwide implementation of folate supplementation of pregnant women in 1990 and the fortification of wheat flour with iron and folate in 1996. The annual incidence of spina bifida fluctuated from 2.34 to 4.03 per 1000 deliveries between 1991 and 1996, but fell sharply to 2.11 per 1000 deliveries in 1997, after which the downward trend continued, reaching 0.29 per 1000 deliveries by 2006. The rate of other neural tube defects remained almost constant. The reduction in spina bifida rates in Oman could be linked to the start of flour fortification but not the supplementation programme.