Introduction. Sansevieria liberica Gerome and Labroy (Agavaceae) is a perennial plant widely distributed in tropical Africa. Preparations of the plant are commonly used across Nigeria for the treatment of inflammatory conditions. Based on the fact that herbal medicine is a strong component of integrative medicine, this study was conducted to evaluate the anticancer activity of root extracts of Sansevieria liberica. Methods. Sulforhodamine B (SRB) in vitro cytotoxicity assay, Sarcoma-180 (S-180) ascites and solid tumor, and L1210 lymphoid leukemia in vivo models were used in this study. Results. SL-A002 (IC50 23 µg/mL with HeLa), SL-A003 (IC50 22 µg/mL with HCT-116), and SL-A004 (IC50 23 and 18 µg/mL with A549 and THP-1, resp.) demonstrated significant activity in the SRB cytotoxicity assay. Potency was highest with the following pairs of extract : cancer cell line: SL-A002 : HeLa (IC50 23 µg/mL), SL-A003 : HCT-116 (IC50 22 µg/mL), and SL-A004 : THP-1 (IC50 18 µg/mL). SL-A002 demonstrated significant dose-dependent antitumor activity in the Sarcoma-180 (S-180) ascites model with peak effect produced at the dose of 120 mg/kg (i.p.) with inhibition of 89.36% compared to 97.96% for 5-FU (20 mg/kg i.p.). The inhibition of tumor growth by SL-A002 in the S-180 solid tumor model was 47.40% compared to a value of 50.18% for 5-FU. SL-A002 was also significantly active in the L1210 lymphoid leukemia model with 158.33% increase in mean survival time, the same value for 5-FU. Conclusions. The hydroethanolic extract of Sansevieria liberica, SL-A002, possesses significant anticancer activity to warrant further extensive study to identify, isolate, and characterize the specific bioactive molecules responsible for the observed antitumor activity and the precise mechanism(s) of action.