Peganum harmala L. is known as Syrian rue, Wild rue and Harmal. P. harmala extracts are considered important for drug development, because they are reported to have numerous pharmacological activities in the Middle East, especially in Iran and Egypt. For a long time P. harmala has been used in traditional medicines for the relief of pain and as an antiseptic agent. P. harmala also have antibacterial, antifungal, antiviral, antioxidant, antidiabetic, antitumor, antileishmanial, insecticidal and cytotoxic activities and hepatoprotective and antinociceptive effects. Harmaline, harmine, harmalol, harman, quinazoline derivatives, vasicine, vasicinone, anthroquinons and fixed oils are reported from seeds and roots of this plant. This plant is used as a medicine in Turkey, Syria, Iran, Pakistan, India, Egypt and Spain. This article presents comprehensive analyzed information on the botanical, chemical and pharmacological aspects of P. harmala.