Two common Pst I and Taq I restriction enzyme fragment length polymorphisms (RFLPs) were detected at the human parathyroid hormone (PTH) gene locus. The allele frequencies in a Northern German population were 0.578/0.422 (Pst I) and 0.628/0.372 (Taq I). The allele distributions follow Hardy-Weinberg expectations of equilibrium in the population. The Mendelian nature of the polymorphisms were confirmed in family studies.