Abstract The 1000 × 200 km Tanganyika-Rukwa-Malawi fractures area is shown to be a right lateral intracontinental transform zone belonging to the East African Rift System. Using the results carried out from complementary techniques (remote sensing, field structural analysis and K-Ar isotopic dating) it appears that tectonics in this area have acted at different times, the oldest being at 2000-1400 m.y., the youngest being still active today, and are mainly due to the reactivation of NW-SE structures. The area consists mainly of large NW-SE “en échelon” dextral transcurrent faults, along which the Southern Tanganyika, Rukwa and Northern Malawi troughs are opening. NE-SW transverse faults showing a curved horizontal shape end these troughs axially. Eocene to recent volcanic activity is associated with the intersection of the northeastern main NW-SE transcurrent fracture (the Livingstone fault).