Oxygen isotope records from lake sediment archives are becoming an increasingly common tool for palaeoenvironmental reconstruction. We discuss their interpretation in the Eastern Mediterranean region with particular reference to three records, Zeribar, Van and Eski Acıgöl during the Holocene. The latter two records have been interpreted as controlled by changes in the precipitation to evaporation ratio, and the first due to changes in precipitation seasonality. In light of recent isotope work in the region and comparison with other proxy data from the same lakes, we show both of these initial interpretations to be oversimplified. Careful interpretations of complex lake isotope systems are therefore required in order that palaeoclimatic inferences are drawn correctly.