The role played since the Early Jurassic by the Marda Fault Zone (MFZ) in the geodynamic evolution of the Horn of Africa is examined. Three main stages of evolution have been recognized: (a) a Tethyan stage (Jurassic/Early Cretaceous): (b) an Indian stage (Late Cretaceous/Eocene); and (c) an Arabian stage (Oligo‐Miocene/Resent).During the Tethyan stage (which is characterized by the distribution of fauna with a Tethyan affinity), the MFZ probably acted as a major deep‐ rooted transfer fault, connecting overstepping segments of en‐éhelon east‐west strike‐slip faults. Crustal stretching, caused by the southwards drift of Madagascar, was active in the SW region of the Horn of Africa. but was relatively negligible in the NE region.During the Indian stage (involving the NEwards drift of India), the MFZ was still aligned, in the Late Cretaceous, with the paleo‐margins of the Red Sea — bgore the rotation of Arabia away from Africa — and with the oceanic spreading ridges developed in the Mascarene Basin of the Indian Ocean. It was in this stage that the MFZ is interpreted as having acted as an incipient aborted rift, causing the rapid subsidence of the NE region of the Horn of Africa, and consequently the onset of a new depositional cycle.During the Arabian stage (separation of Arabia from Africa), there was a sudden change in the geodynamics of the Horn of Africa: crustal stretching of the Red Sea — Gulf of Aden —Ethiopian Rift Valley triple junction occurred, leaving the segment of the MFZ in the Horn of Africa inactive.These three stages correspond with three important tectonic changes in the Indian Ocean and the Western