The invention relates to a method for determining, the sex of at least one embryo in an egg (12), in which the sex of the embryo is determined by means of at least one detection method which is noninvasive at least with regard to the egg (12), wherein at least one oestradiol value which characterizes the concentration of oestradiol in the egg (12) is determined by means of the noninvasive detection method and the sex is determined as a function of the oestradiol value.
