Lymphatic drainage of the testes is known to follow a predictable pathway that usually involves the retroperitoneal, paraaortic, paracaval and interaortocaval nodal chains. Herein we report the case of a 41 years old man with a stage I testicular seminoma, with an unexpected inguinal lymph node metastasis. During his routine follow-up visit, 6 months after radical orchiectomy, a spherical mass in the right inguinal region was palpated. Thoraco-abdominal CT did not reveal any evidence of retroperitoneal enlarged lymph nodes or distant metastases, but showed a 2cm right inguinal mass. Scrotal scintigraphy with technetium-99m pertechnetate was performed in order to evaluate the local vascularity of the right inguinal area. The angiographic phase (0-1min) and the blood pool images at 15, 30, 45 and 60min revealed high uptake in the right inguinal region, suggesting a hyperemic mass suspicious for tumor recurrence. The excised mass was found to be an enlarged lymph node infiltrated with seminoma. The patient received adjuvant radiotherapy to which he showed a complete response and has been disease free at 2 years follow-up. In conclusion, in the case presented scrotal scintigraphy showed a hyperemic mass at the right inguinal region that proved to be the sentinel node of a stage I testicular seminoma and was treated accordingly.