The smear technique of cytodiagnosis is of distinct value in the study of lesions of urticaria pigmentosa, herpes simplex, eczema herpeticum, herpes zoster, varicella, and vaccinia. The method has certain advantages as a rapid aid to the diagnosis of pemphigus vulgaris and pemphigus erythematosus, but pitfalls are encountered because of the presence of acantholytic and Tzanck-like cells in other diseases. Proteolytic enzymes liberated from polymorphonuclear leukocytes or bacteria probably account for the acantholytic cells observed in several of the vesiculobullous and pustular diseases studied. Cytodiagnosis of inflammatory dermatoses is an adjunct to routine histologic study and clinical evaluation of the disease.