We recently suggested that due to insufficient intake of vegetables, low folate status and mild homocysteinemia might exist in the Kazakh population. To clarify the determinants of homocysteine concentrations among this population, we determined concentrations of serum folate, albumin, creatinine, vitamin B12, and the C677T/ MTHFR genotype in 110 Kazakh individuals and compared these with plasma total homocysteine. In Kazakh, after adjustment for age and sex, folate was correlated with plasma total homocysteine, whereas concentrations in those with the TT genotype was almost twice as high as in those with the CC and CT genotypes (19.7+/-1.8 micromol/L vs. 10.7+/-0.5 micromol/L, p<0.001). Our results suggest that the C677T/MTHFR genotype is associated with homocysteine concentrations in this population and this association might be affected by other factors, such as folate status.