Effective supplementation with folate, which prevents neural tube defect (NTD) occurrence, and high homocysteine levels in the blood of NTD children?s mothers suggest that genes involved in folate and homocysteine metabolism can be involved in NTD aetiology. Genes encoding methylenetetrahydrofolate reductase (MTHFR) or methylenetetrahydrofolate dehydrogenase (MTHFD) belong to the first group. Genes encoding methionine synthase (MTR), its regulator ? methionine synthase reductase (MTRR) and also cystathionine synthase (CBS) can be included in the second group. We present a current list of the folate and homocysteine metabolism genes that are known to be involved in NTD and pay special attention to primary and secondary NTD prevention.