Abstract: Objective To study the effect of knocking down fascin on cervical cancer cell proliferation and tumorigenicity in nude mice. Methods Cervical cancer CaSki cells were infected with a lentiviral vector carrying fascin siRNA or with a negative control lentivirus, and fascin mRNA and protein expressions in the cells were detected using qRT-PCR and Western blotting. MTT assay was used to determine the proliferation of CaSki cells with fascin knockdown. CaSki cells transfected with fascin siRNA or the control lentiviral vector and non-transfected CaSki cells were inoculated subcutaneously in nude mice, and the volume and weight of the transplanted tumor were measured; Western blotting was used to detect the expressions of proliferating cell nuclear antigen (PCNA), survivin, cyclin dependent kinase 4 (CDK4) and p21 proteins in the tumor xenograft. Results Infection with the lentiviral vector carrying fascin siRNA, but not the negative control vector, caused significant reductions in the expression levels of fascin mRNA and protein in CaSki cells (P<0.05). Fascin knockdown resulted in significantly reduced proliferation of CaSki cells in vitro (P<0.05). The nude mice inoculated with CaSki cells with fascin knockdown showed reduced tumor volume and weight, lowered levels of PCNA, survivin and CDK4, and increased expression of p21 protein in the tumor xenograft compared with the control mice. The negative control lentivirus did not affect the proliferation or tumorigenicity of CaSki cells in nude mice or the expression levels of PCNA, survivin, CDK4 or p21 proteins in the xenografts. Conclusion Knocking down fascin can inhibit the growth and tumorigenicity of cervical cancer cells in nude mice.