The occurrence of tsunamis, affecting the Portuguese coasts, has been reported since the year 60 BC and the Gorringe bank region has been assumed as the most prone area for tsunami generation in the southwestern Iberian area. The tsunami generated by the 1755.11.01 earthquake is the largest one known in this area, having deeply affected the coasts of Iberia and Morocco. The earthquake, itself, was felt all over Europe, its estimated magnitude being 8.3/4 and its MSK intensity at the epicenter I0=XI-XII.The great similarity between the isoseismal maps of this event and those of the recent 1969.02.28 earthquake lead several authors to locate the epicenter of the 1755 tsunami close to the Gorringe Bank (cf. Fig 1) and to infer the same type of focal mechanism (e.g. Machado, 1966, Martinez Solares et al., 1979, Levret, 1991) as the one deduced for the 1969 event (Fukao, 1973).The correct identification of the tsunamigenic sources is the essential task for the determination of tsunami risk at the Iberian area. The question we try to answer in the present study is whether or not there is only one major tsunami generating area in the western Iberia as it has been assumed until now.The results obtained here suggest that the 1755 tsunami was probably originated on the continental Iberian shelf, implying an epicentre area located between the Gorringe Bank and the Iberian coasts (cf. Fig. 1), closer to the coast. A complex source is proposed in order to justify tsunami observations in Morocco and seismic intensity values along the lberian and north Morocco coasts