Over the past decade,the Mg/Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy.In this study we describe the application of the Mg/Ca paleothermometer with the aim of illustrate its use in the Mediterranean Basin.We value the influence of the salinity and diagenetic carbonate processes besides temperature as an important environmental factor controlling the foraminiferal Mg/Ca.For this purpose 3 species of planktonic Over the past decade, the Mg / Ca ratio in foraminiferal tests has emerged as a valuable paleotemperature proxy. In this study we describe the application of the Mg / Ca paleothermometer with the aim of demonstrating its use in the Mediterranean Basin. We value the influence of the salinity and diagenetic carbonate processes besides temperature as an important environmental factor controlling the foraminiferal Mg / Ca.For this purpose 3 species of planktonic