Plants are common remedies applied by a majority of people. Ethnomedicinal plants are considered new resources for yielding components that could act as alternatives to antibiotics in cure of antibiotic-resistant bacteria. Verbascum thapsus (VT) is a vernacular plant in Iran, which the plant has been used as an antioxidant, antiflammatory, tonic, indigestion, antipyretic, antiviral, and antifungal. In this study, authors describe properties of aqueous extract of VT against common pathogen (Staphylococcus aureus ATCC No. 25923 (SA)) with broth macro-dilution and agar well and disk diffusion methods. The antibacterial activities of the plant was assessed by macro-dilution method in Mueller-Hinton broth medium and agar well and disk diffusion methods. The results revealed that the aqueous extract of VT exhibited strong levels of antibacterial activities against SA. By increasing the concentration of the extract, the inhibition zone in many of samples augmented. Partially, in agar disk diffusion the widest inhibition zone of 15 mm occurred in 0.083 g/ml VT with no inhibition with distilled water. In agar well diffusion, the widest inhibition zone of 13 mm observed in 0.083 g/ml. MIC and MBC of VT were 0.01 and 0.02 g/ml, respectively. Find discrepancies in SA sensitivity to VT with greater inhibition in disk diffusion tests. Our findings indicated that VT aqueous extract had a potential to be applied as antibacterial agent.