Objective: Determine the hospital incidence rate trends for neural tube defects (NTDs) and their types during the pre-fortification period (2001-2005) at the National Maternal-Perinatal Institute of Lima (INMP). Material and method: An observational, descriptive, retrospective, cross sectional study was carried out. Medical histories of newborns and their mothers between 2001-2005 were reviewed. The sampling universe was 93.863 newborns, of which 128 had NTDs. The univariate analysis included the average, standard deviation, and absolute and relevant frequency determination. The comparison between the data for different years was carried out through a Prais Winsten test. The CI of 95% for the global incidence and the types of NTD was calculated through the Poisson Test. Results: NTDs fluctuated between 18 and 32 cases per year, which corresponds to the global hospital rate of 13.6 per 10,000 newborns (CI 95%: 11.38;16.21) between 2000-2005. The incidence of spina bifida was 8.3 x 10,000 (CI 95%: 6.57;10.37), followed by anencephaly with 5.1 x 10,000 (CI 95%: 3.77;6.78) and 0.2 x 10,000 (CI 95%: 0.03; 0.77) for encephalocele. Finally, the tendency of NTDs between 2001 to 2005 showed a not significant increase (p=0.951). Conclusion: The average NTD global incidence rate in the period of 2001- 2005 was 13.6 per 10,000 newborns (CI: 11.38;16.21), showing a not significant rising trend. Myelomeningocele had the highest incidence rate in relation to the other types of NTD.