Peganum harmala, belonging to Zygophyllaceae family, is a herb with medicinal properties. This study evaluates the antioxidant activity of Tunisian Peganum harmala seed extracts obtained by two methods of extraction. The antimicrobial activity was also evaluated. The antioxidant activity of the extracts of Peganum harmala was studied by three different methods, including scavenging activity by DPPH, phosphomolybdenum method and reducing power of iron. The antimicrobial activity was evaluated using the broth microdilution assay. Results show that extract concentration was directly proportional to the antioxidant activity and the extracts of the maceration extraction showed a higher antioxidant activity than that in extracts of the soxhlet extraction. At all concentrations compared with BHT, the hexane extract have a higher antioxidant activity than those of all extracts of Peganum harmala seeds. For the phosphomolybdenum method, all the extracts showed an increase in antioxidant capacity with an increase in dose. A quantitative analysis of polyphenols, flavonoids and tannins was also performed. For the antibacterial activity, all the extracts tested shown an important antibacterial effect expect for the hexanic extract obtained by soxhlet extraction. Indeed, the MIC values of the different extracts ranged from 0.097 to 0.78 % (v/v) against studied strains.