The aim of this study was to evaluate the impact of donor killer cell immunoglobulin-like receptor (KIR) and recipient HLA genotypes on outcome following haploidentical hematopoietic stem cell transplantation (HSCT). 26 patients with hematologic diseases received non T-cell-depleted (TCD) in vitro transplant from haploidentical donor. Donor/recipient HLA and donor KIR genotypes were determined by polymerase chain reaction-sequence-specific primer (PCR-SSP). Donor/recipient KIR/HLA subgroup was assessed by donors KIR and recipients HLA-Bw4, Cw1 group and Cw2 group alleles. Hematopoietic reconstitution, incidence of graft versus host disease (GVHD), disease-free survival (DFS), infection and transplant-related mortality (TRM) were analyzed between every two groups. The influence of donor activating KIR on outcome following haploidentical HSCT also has been studied. The results showed that hematopoietic reconstitution, incidence of GVHD, DFS, infection and TRM were not significantly different between every two groups (p>0.05). There were 4 cases of severe GVHD in C2 mismatched group. The donor activating KIR2DS5 positive group had higher 2-year DFS compared with the negative group [(85.7+/-13.2)% vs (31.2+/-12.8)%, p<0.05]. It is concluded that KIR/HLA genotypes between donor and recipient influence the outcome following haploidentical HSCT. Donor activating KIR2DS5 may improve DFS in non TCD haploidentical HSCT.