A technique for primary plastic embedding for light microscopy was utilized in evaluating plaque lesions in four patients with mycosis fungoides and compared to tissues from the same patients embedded in paraffin. Standard 3 mm punch biopsies were utilized. Specimens were fixed in B‐5 and embedded in araldite epoxy resin. In specimens from all four patients, the cytological details of the mycosis cells were superior in the plastic embedded tissues. This practical and relatively inexpensive method may prove to be a sensitive indicator of mycosis cells in early lesions. This technique also permits the use of a variety of special stains, immunoperoxidase and electron microscopic analyse