Electrodialysis (ED) with bipolar membranes (BPM) was applied for the extraction of amino acids in an electrically neutral form. Under voltage, BPM split water, generating hydroxyl ions at the anodic side and protons at the cathodic side. The use of these membranes represents a newer method to convert neutral species into electrically charged species that are able to cross homopolar ED membranes. The ED operations were performed using a laboratory cell with a membrane area of 50 cm(2). A mixture containing five amino acids (Gly, Ser, Ala, Val, Phe) was examined. The concentration of each amino acid was 100 mmol dm(-3). The current density and pH in the feed and receiver compartments were varied. Extraction degrees and current efficiencies were calculated and compared under different experimental conditions.