We give a detailed account of investigations on the structure of giant monopole resonances in208Pb. A part of the results of this paper has already been published in “Short Notes” in this journal. The calculations are based on a renormalized correlation function technique which turned out to be very suitable for our purposes. The calculations predict an isoscalar resonance atE≈13 MeV and an isovector resonance atE≈20.5 MeV. The width of both states is mainly due to the spreading.