This Canadian Society of Clinical Chemists (CSCC) sponsored position statement addresses the problem of nonuniformity of standardization of polypeptide hormone analyses. First we review the structural diversity of selected polypeptide hormones including growth hormone (GH), prolactin, follitropin (FSH), lutropin (LH), human chorionic gonadotropin (hCG), and thyrotropin (TSH) and the problem that this heterogeneity creates. The history and availability of reference materials for the analyses of these hormones are then summarized. Finally we make a list of recommendations regarding standardization, methods of measurement, and reporting of polypeptide hormone results. Implementation of the recommendations will lead to improvement in inter-laboratory comparability and more useful hormone assays.