In 262 men (about half of them 44.4 +/- 0.9 and 63.0 +/- 0.9 years old, resp.) and 239 women (about half of them 44.4 +/- 0.9 and 62.8 +/- 0.8 years old, resp.) the results of 12 clinical chemical analytes were used to calculate laboratory indices which were compared with the biological age in accordance with Ries. The indices were calculated by using concentrations of alkaline phosphatase, iron, total protein, total cholesterol, glucose, uric acid, urea, HDL cholesterol, creatinine, LDL cholesterol, transferrin, and triglycerides. Only in the younger group of women are the correlations between laboratory indices and biological age significant. In the same group, several single parameters also significantly correlate with pre-aging. Among them are alkaline phosphatase, the LDL-C/HDL-C ratio, bilirubin, triglycerides, and glucose.