The Mendana Fracture Zone is a major intra-oceanic feature on the Nazca Plate off Peru. During the Seaperc cruise of R/V Jean charcot in 1986, Seabeam bathymetric data, single channel seismic records, geomagnetic and gravity measurements and heat flow data were obtained over this area. In this paper, we show that the Mendana Fracture Zone is actively opening perpendicular to its trend, resulting in the formation of new oceanic crust since about 3.5 Ma. This new rift is propagating westward along the fracture zone at a velocity of about 17 cm/yr with respect to the trench). The origin of the Mendana spreading centre would be the extensional stress acting parallel to the Peru Trench in this area.