Background and objectives: Neural tube defects (NTDs) are common congenital anomalies caused by genetic, environmental, or nutritional factors. Normal plasma folic acid levels in the fetus are required for proper development of the neural tube. Plasma folic acid level has an inverse relationship with homocysteine level. This study aimed to determine plasma folic acid and homocysteine levels in babies born with NTDs and healthy controls. Methods:The study included 30 clinically diagnosed NTD cases and 30 healthy age-and sex-matched control subjects. Plasma levels of folic acid and homocysteine were measured using a direct chemiluminescence method. Data were compared using the independent t-test. Statistical analysis of data was performed using GraphPad InStat 3.0 at significance of 0.05 Results:The mean plasma level of folic acid in NTD cases (5.1±4.9 mol/l) was significantly lower than that in healthy controls (19.5±2.1 mol/l) (p<0.05). The mean plasma level of homocysteine in NTD cases (14.3 ± 2.4 ng/ml) was significantly higher than that in healthy controls (4.9±1.8 ng/ml)(p<0.05). The mean plasma level of folic acid was 20.1±1.5 µmol/l, 8.5 ±2.9 µmol/l, and 1.9 ±0.4 µmol/l in mild, moderate, and severe cases of NTD, respectively. The mean plasma level of homocysteine was 10.7±3.4 ng/ml, 15.4±1.2 ng/ml, and 18.5±0.8 ng/ml in mild, moderate, and severe cases of NTD, respectively. Conclusion: Low level of folic acid and high level of homocysteine are directly associated with the development of neural tube abnormalities. Moreover, the severity of the NTD is inversely related to plasma level of folic acid and directly related to plasma level of homocysteine.