We investigated total homocysteine (tHcy) concentrations and relations between tHcy and folate, cobalamin (Cbl), genetic polymorphisms (MTHFR 677C > T, MTHFR 1298A > C, MTHFR 1793G > A), blood pressure (BP), body mass index (BMI), cholesterol, triglycerides, sports activities, family and individual history of cardiovascular disease (CVD) and lifestyle issues in 264 healthy children and adolescents (2-17 y). THcy concentrations significantly increased while folate and Cbl decreased with age without gender differences. Age, folate and Cbl were significant predictors for tHcy concentrations. THcy was higher but within normal ranges in MTHFR 677TT homozygotes (10.6%) and carriers of the MTHFR 1793A allele (8%). Only two individuals (0.8%), both with low tHcy concentrations, were homozygous for MTHFR 1793AA. THcy concentration correlated positively with creatinine, triglycerides, BMI and systolic BP and was not related to cholesterol, sports activities and family history of CVD. In conclusion, tHcy concentrations in this pediatric population were significantly influenced by age, folate and Cbl concentrations. No gender differences for tHcy, folate or Cbl concentrations were observed. Both the MTHFR 677TT genotype and the MTHFR 1793A allele were not associated with hyperhomocysteinemia. The prevalence of the MTHFR 1793AA genotype was too low for meaningful interpretation.