Fossil and subfossil diatom floras were analysed in a sediment core taken near the outlet of the Faroe Bank Channel, NE Atlantic. Diatom preservation horizons were found at various levels in the core. The correlation with the oxygen isotope stratigraphy of the core indicates that these horizons correspond to the Marine Oxygen Isotope Sub-Stages 5e (Eemian), 5a and Stage 1 (Holocene). Results of the study show that environmental conditions for the development of diatoms were more favourable in Stage 5 than in the Holocene. At the very beginning of the Sub-Stages 5e and 5a distinct changes in the diatom concentration are indicative of circulation changes probably associated with a marked intensification of the North Atlantic Current. The highest surface water temperature is indicated by the diatom flora from early Sub-Stage 5e.