► Antioxidant potential and antiproliferative effect of five monoterpenes was investigated. ► α-Terpineol presented good antioxidant activity in ORAC test. ► Limonene and α-terpineol presented equivalent antiproliferative profile in vitro. ► α-Terpineol had encouraging results against breast carcinoma and chronic myeloid leukemia. ► In vivo assays must be performed to confirm the anti-tumor potential of α-terpineol. α-Terpineol is a relatively cheap and abundant aroma compound. It is widely used in food, cosmetics, and household products. Many of its monoterpene counterparts have been applied in antiproliferative assays, leading to promising results in the prevention or even treatment of cancers. However, despite its theoretic potential, no paper reports the evaluation of antiproliferative capacity of this alcohol. Thus, antioxidant potential of three monoterpenoids (carvone, perillyl alcohol, and α-terpineol) was measured using two methods: DPPH and ORAC. Also, the antiproliferative effect of these monoterpenoids against nine cancerous cell lines were performed and compared to limonene and doxorubicin. Results showed that all samples tested had very low antioxidant activity in the DPPH assay, but α-terpineol (2.72μmolTrolox equiv./μmol) could be compared to commercial antioxidants in the ORAC assay. The antiproliferative results obtained encourage future in vivo studies for α-terpineol, since this monoterpenoid presented cytostatic effect against six cell lines, especially for breast adenocarcinoma and chronic myeloid leukemia, in a range of 181–588μM.