Our work includes a total of 70 cases of endodermal sinus tumor (EST) of the testis which 25 are pure and 45 combined. The mean age of the patients was 6 in the pure and 31 in the combined form.21 out of the 25 pure cases were encountered in children under 4 years of age. The youngest patients was 10 months old in the pure form, 15 months old in the combined /form. The oldest patients were 35 and 65 years old respectively. The pure form of EST constitutes 3.9 % of pure germ cell tumors and in 22.2 % of combined germ cell tumors we have seen an EST component. Macroscopically in 60 % of the pure and in 24 % of the combined form the tumor was smaller than 5 cm. In the pure form typical histopathologic findings were mic. rocystic, myxomatous, papillary, solid, alveolar-glandular structures, perivascular structures (Schiller-Duval bodies) and polyvesicular structures. In the combined form the EST component was encountered in various proportion and in order of frequency in 1 case polyembryoma, in 7 choriocarcinoma, in 11 embryonal carcinoma, in 11 seminoma, in 30 immature teratoma, in 36 mature teratoma was associated with EST. We wish to emphasize the importance of a careful examination, sampling and serial sections in order to find out EST, embryonal carcinoma and choriocarcinoma components which their presence have crucial prognostic significance in combined germ cell tumor cases.