Allogeneic natural killer (NK) cell immunotherapy is recognized as a promising anti-tumor strategy, but whether it plays a role in poor CD4 recovery among human immunodeficiency virus type 1 (HIV-1) infected patients is unknown. This study aimed to investigate the safety and effectiveness of allogeneic NK cells immunotherapy on HIV-1 immunological non-responders (INRs) receiving antiretroviral therapy (ART). From February to April 2018, a prospective, randomized, controlled, open-label clinical trial, which enrolled 20 HIV-1 INRs following specific inclusion criteria, was conducted at Nankai University Second People's Hospital. Participants were randomly allocated (simple randomization 1:1) to either the combined treatment (NK + ART) group (n = 10) or the control (ART) group (n = 10). The allogenic highly activated NK cells from killer cell immunoglobulin-like receptor (KIR)/human leukocyte antigen (HLA)-Cw mismatched healthy donor were prepared (10 cells in each injection) and intravenously infused to each recruited patient of NK+ART group in three courses. Key immune parameters (CD4 count, CD8 count, CD4/CD8 ratio), laboratory tests (count of blood cells, biochemistry panel) and symptoms at baseline and at month 1, 3, 6, 9, 12, and 24 were measured/collected to analyze the safety and efficacy of the therapy. Comparisons were between the seven time-points of both groups using repeated measurement analysis of variance (ANOVA) test. Generalized estimating equations (GEE) model was performed to evaluate the overall effect of the NK+ART group vs. the ART group. From baseline to 24 months, we noted a mean CD4 count augmentation (139 to 243 cells/μL) in the NK + ART group and (144 to 176 cells/μL) in the ART group (difference, 67; 95% CI, 10 to 124; P = 0.024). Our estimations revealed that NK+ART group could improve CD4 level (β = 54.59, P = 0.006) and CD8 level (β = 322.47, P = 0.010) on average among the six measurements compared with the ART group. Only two (2/10, 20%) participants in the NK+ART group developed a transient mild fever after the first course. This preliminary study informs that HIV-1 INRs, allogenic NK cells immunotherapy is safe and could significantly improve CD4 recovery but not CD4/CD8 ratio. The practical effects, however, need long-term follow-up observations. Further study on the potential underlying mechanism is warranted. REGISTRATION INFO:: www.chictr.org.cn/showproj.aspx?proj=34912 (No. ChiCTR1900020634).