Stage I seminoma represents the paradigm of a curable malignancy, with survival of 100% an expected outcome no matter what treatment option is chosen. However, consensus has not been reached among urologists and oncologists regarding the optimal postoperative management in men with clinical stage I testicular seminoma. Currently, men are offered active surveillance, adjuvant radiation therapy, or single-agent chemotherapy. Active surveillance is associated with an 80% chance of no relapse, with all such events salvageable. Radiotherapy has an almost universal cure rate but has the potential for long-term toxicities and an overtreatment rate of about 80%. Chemotherapy efficacy and toxicity data are still immature. Recent guidelines recognize that the options of surveillance, chemotherapy, and radiotherapy are appropriate in the treatment of patients with clinical stage I seminoma. We believe active surveillance to be the best option, then radiotherapy (considering the efficacy and safety data), with single-agent chemotherapy emerging as a possible alternative.