Water mass distribution and geostrophic circulation off Namibia are presented for April 1986, a month of relatively strong warm water intrusion from the north and west. The main result is that mesoscale processes develop in the area during the season when the coastal upwelling is relaxed, and these processes may be an alternative contribution to the fertilization of the region. The main features observed are the following. Angolan waters entered the region through the surface layer, with a maximum flow at 50 m depth. A frontal zone, centered between 20°S and 22°S separated Angolan and Benguela waters, at the surface layer. Anticyclonic eddies with a radius of 15-30 miles occurred off central and southern Namibia. Water upwelling off Walvis Bay appeared to derive from the core of the Angolan water, which laid at a depth of 50-100 m. Anticyclonic gyres might contribute to the upwelling off Walvis Bay and to the occurrence of a local sinking in its centre, about 50 miles offshore, thus allowing long residence time and recirculation. The occurrence of eddies may have been related to the general relaxation of the Benguela Upwelling System in the preceding 3 months and the penetration of the Angolan waters, in the region north of Walvis Bay, while in the south, the meanders of the oceanic front may remain most important.