The granulocytic antigens NA1 and NA2 are two allelic gene products of the FcgammaRIIIB gene. These antigens are frequently targets of granulocytic-specific allo-antibodies and auto-antibodies that cause neutropenias. Different distributions of these antigens have been found in population studies. In our study, the genomic DNA of 345 healthy, unrelated Spanish individuals was typed for NA1 and NA2 using polymerase chain reaction (PCR) with sequence-specific primers (SSP). The gene frequencies found in the Spanish population were 0.29 for NA1 and 0.71 fo NA2. Flow cytometry immunotyping was also carried out in 20 of these samples, and an exact correlation was observed among the results. The gene frequencies determined in our study are similar to those reported in other Caucasian populations. The null phenotype reported in other serological studies was not found. This typing system can be used in population studies instead of serological tests as a more rapid, simple and reproducible method.