Objective Measuring serum and cerebrospinal fluid human chorionic gonadotropin (hCG) is essential for the diagnosis of intracranial germ cell tumors. There are three types of hCG-related markers in clinical use: hCGβ, intact hCG, and total hCG. The best marker for the diagnosis of intracranial germ cell tumors, especially germinoma, is currently unknown. This study aimed to evaluate the usefulness of these hCG-related markers. Materials and Methods We report six patients with histologically diagnosed germinoma treated at our institute. Serum hCGβ, intact hCG, and total hCG were measured before, during, and after treatment. Results The positivity rates of serum hCGβ, intact hCG, and total hCG were 6% (1/17), 47% (7/15), and 42% (8/19), respectively, with the latter two having significantly higher positivity rates than hCGβ (p = 0.041). Both intact and total hCGs showed similar values. The median value of hCGβ, intact hCG, and total hCG before treatment was 0.1 ng/mL, 4.6 mIU/mL, and 4.5 mIU/mL, respectively. Conclusion Serum intact and total hCGs have higher detection rates than hCGβ for patients with germinoma using available commercial measurement tools.