The killer immunoglobulin-like receptor (KIR) genes KIR2DL4, KIR3DL2, and KIR3DP1 are present in virtually all humans. KIR2DL4 encodes a receptor present on uterine and decidual natural killer (NK) cells and some peripheral blood NK cells. Its only known ligand is the human leukocyte antigen-G molecule expressed on extravillous trophoblasts, and on tissues in some diseases. KIR3DL2 binds HLA-A*03 and HLA-A*11 as well as HLA-B*27 dimers, and microbial CpG DNA. KIR3DP1 is a pseudogene. During our immunogenetic studies we found two individuals, one from Lower Silesia district in Poland, and another from Western Ukraine, who were reproducibly negative for KIR2DL4 and KIR3DP1 genes, using three different PCR systems. Both individuals displayed very similar genotypes, possessing only KIR3DL3, KIR2DL3, KIR2DP1, KIR2DS1, and probably a rare variant of KIR2DL1. The Pole had also KIR3DL2, which the Ukrainian was apparently lacking. The Lower Silesia has been populated after the Second World War by a remarkable percentage with displaced people from Western Ukraine, which might contribute to genetic similarity of the two individuals described here.