Lipids were isolated from psoriatic scales. Positional isomers of hcxadecenoic» octadccenoic and octadecadienoic acids of the cholesterol esters and triglyccrides were determined by oxidative cleavage (MnO4/lQ,). The following hcxadccenoic acids were present: 4-hcxadecenoic acid (1.5%), 6— (10.6%), 7— (2.7%), 8— (1.1%), 9— (83.3%), 10— (0.8%), 11— (trace). Among the octadeccnoic acids 8— octadeccnoic acid (4.2%), 9— (81.3%), 10— (3.7%) and 11— (10.9%) could be observed, whereas 8.11-octadecadienoic acid (5.1%), 9.12— (91%), 10,13— (0.1%) and 11.14— (3.8%) were detected. The fat, separated from the psoriatic scales, contains only very little 6-hcxadecenoic acid which is specific for skin fat, but it is very similar to human depot fat. Nach Isolierung der Lipide aus Psoriasisschuppen wurde die Zusammensetzung der isomeren Hexadecen-, Octadecen- und Octadecadiensauren der Cholesterinester und der Triglyceride durch oxydativc Spaltung mit MnO4/IO4 bestimmt. Die Feinstruktur der Hexadecensauren zeigte das Vorkommen von 4— (1^5%), 6— (10.6%), 7— (2.7%), 8— (1.1%), 9— (83.3%), 10— (0.8%) und 11-Hexadecensaure (Spur). Die Octadecensauren erwiesen sich als Isomerengemisch aus 8— (4.2%), 9— (81.3%), 10— (3.7%) und 11-Octadecensaure (10.9%), wahrend bei den Octadecadiensauren 8.11— (5.1%), 9.12— (91%), 10.13— (0.1%) und 11.14-Octadecadiensaure (3.8%) nachgewiesen wurden. Das aus Psoriasisschuppen isolierte Fett zeigt eine auffallige Ahnlichkeit mit menschlichem Depotfett und enthalt nur wenig 6Hexadecensaure, die spezifischer Bestandteil menschlichen Hautfettes ist. Psoriasis (psoriasis vulgaris) is characterized by an increased production o£ epidermal skin tissue which leads to a strong production of scales. Though the cause of this disease is still unknown some details of it (certain inheritance, therapeutic effects of high energy radiation and diet) lead to the conclusion that one should look for a metabolic effect resulting from a genetic defect. (1). Nevertheless an infection is still not excluded as a possible cause. In the case of a genetic defect in the synthesis or regulation of enzymes, at least a quantitative difference between the metabolism of normal and psoriatic skin should be observed. This paper deals only with the lipid metabolites, and the possibility remains that the defect could also be revealed by changes in the protein, nucleic acid or carbohydrate metabolism.