It was to explore the immune outcome of co-culture of dendritic cells (DC) and cytokine-induced killer cells (CIK) on prostate cancer (PCa) cells. Peripheral blood mononuclear cells (PBMCs) were extracted from healthy blood donors. DC and CIK cells were induced and co-cultured. The proliferation and phenotypic changes of DC, CIK, and DC-CIK cells/groups were observed. Model rats were constructed by injecting PC3 PCa cells into the abdominal cavity. The successful 50 cases were divided into a negative control group, a chemotherapy group, a DC group, a CIK group, and a DC-CIK treatment group (each consisting of 10 rats) to observe tumor progression. The secreted concentrations of interleukin-12 (IL-12) ((103.67 ± 2.77) pg/mL) and interferon-γ (IFN-γ) ((730.09 ± 23.52) pg/mL) were higher in DC-CIK group as against DC and CIK groups; the proliferation of CIK was higher in DC-CIK group as against CIK within 12 to 20 days of culture. The positive rate (PR) of CD3/ CD56 and CD8 was higher and that of CD45RA was lower in DC-CIK group as against CIK.The killing rate of the DC-CIK group was higher than that of the DC and CIK groups at a target effect ratio of 10:1/20:1/50:1 (P < 0.05). After the treatment, the body weight of rats in the chemotherapy group, DC group, and CIK group was significantly reduced (P < 0.05), while no significant changes were observed in the negative control group and DC-CIK group (P > 0.05). After 25 days of treatment, the tumor size in the DC-CIK group was significantly smaller compared to the negative control group, chemotherapy group, DC group, and CIK group; the necrotic area of the tumor tissue in the DC-CIK group was also significantly larger than that in the negative control group, chemotherapy group, DC group, and CIK group (P < 0.05). Co-culture of DC and CIK is excellent in enhancing the proliferation of CIK cells, increasing the secretion of IL-12 and IFN-γ, and enhancing the activity of immune cells and anti-tumor ability, showing its potential in anti-PCa tumor immunotherapy.