A reproducible technique that provides sections of decalcified rat incisors for electron microscopy is described. Fixation is accomplished by perfusion with slightly hypertonic, neutral phosphate-buffered 2.5% glutaraldehyde for 30-60 min. Throughout the rest of the procedure, isotonic neutral solutions are used. For decalcification, 4.13% disodium ethylene diamino tetraacetic acid for 14-21 days is employed, followed by washing in phosphate buffer for 2 days, postfixation in 1% osmium tetroxide for 4 hr and embedding in Epon. Provided that the initial fixation by perfusion is good, the method gives satisfactory preservation of the fine structures of the cells and matrices of the incisor, in addition to maintaining the relationship of hard and soft tissues.