Fine needle aspiration (FNA) biopsy was performed preoperatively on 13 patients with testicular germ cell tumors. The cytologic typing of the tumors was based on the presence or absence of seminoma, embryonal carcinoma, yolk-sac tumor, choriocarcinoma and teratoma in the aspirate. The cytologic findings showed good agreement with the histologic findings. Only four cases showed a single type of tumor; the other nine cases showed as many as four different tumor components. A few characteristic cytologic features proved to be sufficient for tumor typing; this suggests that FNA biopsy cytology can also be useful in identifying metastatic germ cell tumors in extra-gonadal sites.