Osteocalcin concentrations were measured in 40 healthy males and 60 healthy females aged 21-90 years by a commercial RIA kit. No significant difference between sexes was found for osteocalcin, and a negative and exponential regression with age existed only for females. In comparison to reference values of other investigators, higher osteocalcin concentrations were observed and considered consequential to sample selection and wide age range. Validity of the established reference range (1-18 ng/mL) was confirmed by measuring osteocalcin in patients with different bone metabolism disorders.