Pernicious anemia affects primarily elderly northern Europeans, but may affect others more often than previously thought. Therefore, we analyzed the data from 156 documented cases: there were 73 patients of "European" origin, 52 black patients and 31 Latin-American patients. The mean age (+/- 1 S.D.) at presentation among black women, 53 +/- 16 years, was lower than that of all the others (P less than 0.001 in most comparisons), and seven of the 33 black women were less than 40 years old. In addition, 23 of the 24 black women tested had circulating antibody to intrinsic factor. A similar though less striking antibody prevalence (85 per cent) and age pattern (60 +/- 13 years) in Latin-American women did not reach statistical significance. No other group exceeded the usual 55 to 70 per cent prevalence of antibody. These finding suggest a different form of or a different response to the disease in black women and perhaps in Latin-American women.