Adjuvant radiotherapy, surveillance, and single-agent carboplatin chemotherapy are all accepted treatment options for clinical stage (CS) I seminoma with cure rates approaching 100%. Low-dose (25-35 Gy) adjuvant radiotherapy to the retroperitoneum and ipsilateral pelvis has been the mainstay of treatment for decades and is associated with excellent long-term survival and acceptable short-term toxicity. The use of lower radiation doses (20 Gy) and the omission of pelvic radiation have been investigated to reduce toxicity. However, the risk of late toxicity (specifically cardiovascular disease and secondary malignant neoplasms) resulting from radiation exposure have diminished the appeal of this approach, particularly given the fact that 80-85% of patients are cured by orchiectomy. The appeal of surveillance is the avoidance of treatment-related morbidity in 80-85% of patients and the successful salvage of relapses with 30-35 Gy radiotherapy in most cases. However, given the prolonged time course to relapse in CS I seminoma on surveillance, long-term follow-up with frequent abdominal-pelvic imaging is required. Single-agent carboplatin is associated with comparable short-term relapse rates to adjuvant radiotherapy with the potential for decreased long-term toxicity. However, concerns about the risk of inadequate therapy and late toxicity limit the acceptance of this approach until long-term results are available. With potential of avoiding treatment-related toxicity without compromising curability and given the overall low risk of occult metastasis in clinical stage I seminoma, surveillance is the recommended treatment option. Adjuvant dog-leg radiotherapy is the preferred approach for non-compliant patients or those unwilling to go on surveillance.