Volhard and Fahr recognized that hypertensive intrarenal vascular disease could be divided into two groups corresponding to the clinical states of benign and malignant hypertension. Since that time, numerous papers on malignant hypertension, primarily dealing with European derived populations, have emphasized fibrinoid necrosis of small arteries and arteiroles as the lesion of malignant hypertension, although some have also recognized a myxoid intimal lesion as characteristic. Today in the United States, however, a significant proportion of malignant hypertension occurs in blacks. In the present study, patients have lacked fibrinoid necrosis of arterioles and only rarely have had some atypical necrosis of small arteries. The prominent, but not pathognomonic, lesion in this series is a myxoid intimal thickening of small arteries consisting of smooth muscle cells, acid mucopolysaccharides, basement membrane-like material, collagen, and other amorphous and unidentified material, probably plasma derived.