Twenty compounds were detected in the essential oil of Rhanterium suaveolens representing 98.01% of the total oil content. Perillaldehyde (45.79%), caryophyllene oxide (24.82%) and -cadinol (5.61%) were identified as the main constituents. In -carotene-linoleic acid assay, both the oil and the methanol extract exhibited good lipid peroxidation inhibition activity, with IC50 values of 17.97 +/- 5.40 and 11.55 +/- 3.39g/mL, respectively. In DPPH and CUPRAC assays, however, the methanol extract exhibited a good antioxidant activity. The highest antibiofilm activity has been found 50.30% against Staphylococcus epidermidis (MU 30) at 20g/mL for essential oil and 58.34% against Micrococcus luteus (NRRL B-4375) at 25mg/mL concentration for methanol extract. The in vitro anticholinesterase activity of methanol extract showed a moderate acetylcholinesterase inhibitory (IC50=168.76 +/- 0.62g/mL) and good butyrylcholinesterase inhibitory (IC50=54.79 +/- 1.89g/mL) activities. The essential oil was inactive against both enzymes.