Background: Alpha-terpineol is monoterpene alcohol with anti-tumor activity against different tumor cell lines (lung, breast, leukemias and colorectal) through blockage of NF-kB expression, which play an important role in tumor cells growth. Objective: Evaluate the antitumor activity of alpha-terpineol in murine Sarcoma 180 cell line Methods:: For the tests, different cytotoxic and genotoxic assays were used, including Trypan blue, cytokinesis- blocked micronucleus assay, comet assay, agarose gel DNA fragmentation, flow cytometry and cell viability using fluorescence. Ascitic fluid cells from sarcoma 180 were obtained from Mus musculus peritoneal cavity and Alpha-terpineol was tested at 100, 250 and 500 μg/mL. Doxorubicin and Cisplatin were used as positive controls. Results: Cytotoxic effects of alpha-terpineol were found in all concentrations tested, reducing cell viability in 50.9; 38.53; 30.82% at 100, 250 and 500 μg/mL, respectively. Alpha-terpineol induced genotoxic effects due to DNA fragmentation (increased frequency and index of damage), and was clastogenic by increased micronuclei formation, nucleoplasmic bridges and nuclear buds. DNA fragmentation and increased cell death indicated that alpha-terpineol can cause early, late, and necrotic apoptosis. Conclusion: Our data indicate that alpha-terpineol has antitumor activity revealed by cytogenetic mechanisms and / or loss of cell membrane integrity.