Age structure, growth, reproduction and diet of the whiting, Merlangius merlangus euxinus, were studied on a total of 598 whiting between December 2004 and November 2005 in the southeastern Black Sea. The total length of females was statistically higher than the one of males (t test, p < 0.001). The age range estimated was up to 6 years for females and 5 years for males. To obtain reliable estimates of growth parameters, three growth models (von Bertalanffy, Gompertz and Richards) were applied for both sexes. Gompertz (AIC = 1901.46) and von Bertalanffy (AIC = 1853.71) were the most suitable models to fit age-length data for females and von Bertalanffy considered as the most suitable growth model due to goodness of fit for males. Spawning occurred throughout the year with three peaks: firstly end of winter, secondly middle of spring and thirdly end of autumn. Whiting mostly feed on three fish species: anchovy (IRI% = 35.01), whiting (IRI% = 34.07) and sprat (IRI% = 22.81). ANOSIM showed that significant differences in the prey species composition existed between the seasons (R = 0.1149, p < 0.001) and SIMPER analysis also revealed that the most contributing species to the differences between seasons was anchovy.