Stable isotope records of coexisting benthic foraminifers Uvigerina spp. and Cibicidoides spp. and planktonic G. ruber (white variety) from Site 724 are used to study the late Pleistocene evolution of surface and intermediate water hydrography (593 m water depth) at the Oman Margin. Glacial-interglacial δ18O amplitudes recorded by the benthic foraminifers are reduced when compared to the estimated mean ocean changes of δ18Oseawater. Epibenthic δ13C remains at its modern level or is increased during glacial times. This implies that Red Sea outflow waters which are enriched in δ18Oseawater and δ13OΣCO2 have been replaced during glacial periods by intermediate waters still positive in δ13CΣCO2 but more negative in δ18Oseawater. Glacial-interglacial amplitudes of the planktonic δ18O record exceed those of the mean ocean δ18Oseawater variation and imply decreased surface water temperatures (SST) during glacial times. Throughout most of the records these cooling events correlate with enhanced rates of carbon accumulation.