In a sample of n = 160 nonrelated male and female patients suffering from psoriasis Vulgaris, blood serum protein, and enzyme group typings have been carried out and compared with healthy controls from the same area (Rheinland-Pfalz). Marked statistically significant differences between patients and controls were found in none of the genetic blood polymorphisms considered here. However, combining previously published data from various authors with our own, significant associations between this skin disease and genetic polymorphisms such as MN, Gc, Gm (2), red cell acid phosphatase, and red cell phosphoglucomutase (PGM1) were seen. The possible reasons for these associations are discussed.