Testicular germ cell tumors (TGCTs) are a diverse group of neoplasms that can be divided into seminomas and nonseminomas. Seminomas are the most common form of TGCT, and are presented as homogeneous population of undifferentiated tumor cells. Nonseminomas include four histological subtypes: embryonal carcinoma, choriocarcinoma, yolk sac tumor, and teratoma. (Micro)environmental and (epi)genetic factors are thought to lead to their development. Biomarkers are used to detect different histological subtypes and to make an accurate diagnosis. Because existing biomarkers are not sensitive and specific enough, scientific research and clinical practice point to the need to develop new, more precise biomarkers. In this thesis, the potential of SALL4 and HOXA9 antigens as diagnostic tissue biomarkers was investigated. I used histological staining methods, immunohistochemistry, morphometry and statistically processed the data. According to the obtained results, a significant level of SALL4 antigen expression was demonstrated in embryonal carcinoma, yolk sac tumor, seminoma and in germ cell neoplasia in situ. HOXA9 was demonstrated in all components of TGCT and healthy tissue, especially in choriocarcinoma and teratoma. By combining the staining of both antigens, we can detect all histological subtypes of TGCTs.