Research into the value of transvaginal echography in the diagnosis of endometrioid ovarian cysts has shown that this pathology is characterized by the presence of a round or oblong formation, filled with small-dotted suspension of mean or high echogeneity, by a dense hyperechogenic component of small sizes and wall thickening up to 0.2-0.3 cm. The accuracy of diagnosis of endometrioid ovarian cysts was 92.3%.