The composition of new vaccines against Neisseria meningitidis serogroup B is based on differences in the variable regions VR1 and VR2 of the class 1 outer-membrane protein (PorA) of meningococci. Genosubtyping of 96 N. meningitidis B isolates from blood or cerebrospinal fluid from 2000 to 2003 in the north of Spain allowed characterization of all the strains. Twenty-six genosubtypes or distinct PorA types were obtained. The most prevalent were P1.5-1, 10-8 (20 strains), P1.19, 15 (14 strains), P1.22, 9 (11 strains) and P1.5, 2 (nine strains), while 17 genosubtypes were represented by only one or two strains. The wide diversity of genosubtypes observed and their differences compared with those found in other regions reveals the difficulty in designing a useful outer-membrane vesicle vaccine applicable to different regions of the world.