Zone electrophoresis of serum proteins is still widely performed as a routine procedure in clinical laboratories. It is used in the diagnosis and management of many disorders, e.g. monoclonal gammopathies, cirrhosis, nephrotic syndrome, acute-phase reaction, immunoglobulin deficiency and others. The aim of this work is to evaluate the analytical performance of zone electrophoresis of serum proteins carried out in the Helena Laboratories Rapid Electrophoresis analyser (REP) comparing the results with those obtained in the Olympus Hite System 200 (HS-200). The REP system employs agarose gel as support medium, the HS-200 system employs cellulose acetate and it is the routine method in our laboratory. To date, we have not found any paper that deals with the assessment of a system for performing zone electrophoresis of serum proteins in terms of comparison with another.