Satureja macrantha C.A.Mey. is a medicinal plant which produces essential oils with antibacterial and antifungal activity. This study was carried out to determine the chemical composition of essential oils obtained from four Satureja macrantha populations growing in Iran, and to evaluate their antioxidant and antibacterial activities. The essential oils were obtained by hydrodistillation and analyzed by GC-FID and GC/MS. The main identified constituents were p-cymene, γ-terpinene, thymol and carvacrol. Although the population from Khodafarin was rich in thymol (36.5%), the population from Arasbaran showed a high content of p-cymene (34.7%). In comparison, the populations from Marand and Kaleybar possessed high quantities of carvacrol (42.4% and 48.6%, respectively). The radical scavenging activity against the DPPH radical was noteworthy with IC50 values in the range of 5.6â62.9 µg/mL. The essential oils displayed minimum inhibitory and minimum bactericidal concentrations in the range of 4.6â37.5 µg/mL.