Hexane, chloroform, water extracts and essential oil obtained from flowering aerial parts of Thymus transcaucasicus Ronniger were screened for potential in vitro antioxidant, antimicrobial and antiviral activities. Chemical composition of essential oil was determined by employing GC-MS analysis; thymol being the main component in 55%. The essential oil and extracts were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and beta-Carotene color bleaching test-a spectrophotometric method. The highest free radical scavenging activity was observed in the essential oil (IC50: 20 mu g/ml) whilst, in beta-Carotene color bleaching test, hexane extract showed superiority, with an inhibition rate at 72.3%. Antibacterial and antifungal activities of the extracts were also evaluated and among which the essential oil exerted better activity against all microorganisms tested except for Pseudomonas aeruginosa. Nevertheless, none was effective against test viruses, namely HSV and Influenza.