Inflammation is one of the most important body responses provided by the immune system since it ensures survival when tissues are affected by injuries or infections. The inflammatory response is an important process for maintenance of normal tissue homeostasis. In contrast to acute inflammation, chronic inflammation does not have a useful impact. Prevention and suppression of inflammation are necessary to reduce patient suffering and to preserve the integrity of multiple organs. Unfortunately, commercial available anti-inflammatory drugs are not free from side effects. Hence, there is an urgent need for introducing potent, nontoxic or less toxic antiinflammatory drugs. Recently, substantial progress has been made in the understanding of inflammatory mechanisms which may open new avenues for the preparation of novel anti-inflammatory drugs. Medicinal plants are also promising sources for preparation of such novel drugs. Taking into consideration the anti-inflammatory activities of a large group of medicinal plants, this article, in addition to describing recent advances in progress in understanding the molecular basis of inflammation, presents the most important medicinal plants with antiinflammatory activity.