We have compared six different solutions commonly used for the extraction of peptides to optimize the extraction of Epidermal Growth Factor (EGF) from mouse submandibular glands. The yield of EGF was always higher in neutral pH extractions than in acidic ones. However, the EGF extracted at neutral pH was only poorly adsorbed on to octadecylsilyl silica, whereas the EGF extracted at acidic pH was be easily adsorbed. Subsequent purification of the EGF extracts by two-stage reversed-phase High Performance Liquid Chromatography yielded highly purified EGF. Identical chromatograms were obtained from each of the different extracts. Preparative scale quantities of EGF could be purified rapidly and reproducibly at high efficiency from acidic extracts.