Three cases of xantho-erythodermia perstans (X.E.P.)* seen by the author in the span of 27 years are reported, and this paper constitutes the first written report confined to this subject in the American literature. X.E.P. which has been used only as a synonym in dermatology textbooks, is a distinctive and striking color variant of parapsoriasis en plaques disséminées. The absence of noticeable cutaneous infiltration, pruritus, and lymphadenopathy helps to eliminate the clinical diagnosis of the premycotic or mycotic phase of mycosis fungoides with which it has been confused for many years. Patient 3 in this report has had the eruption for 20 years and has been followed for 14 years, in which time she has as yet not developed cutaneous infiltration, pruritus, or lymphadenopathy. Biopsies of the skin taken in 1948 and again in 1962 show little change nor any tendency to alterations that might cause consideration of the diagnosis of mycosis fungoides up to this time. Thus, this report helps to discount the fact that all cases of parapsoriasis en plaques disséminées become mycosis fungoides. Stains for hemosiderosis have been consistently negative. No clue to etiology has been uncovered. No x-ray therapy has ever been given, and there was no response to substantial therapy with calciferol. Oral and topical corticosteroid therapy produced a diminution in color intensity but did not clear the eruption. Because of the unusual cutaneous color pattern, the diagnosis of X.E.P. should be considered when cases of this type are seen.