About 80% of men with seminomatous testicular germ-cell cancer are diagnosed with stage I disease. For many years, the standard treatment for this patient group has been radiation to para-aortic and iliacal lymph nodes at the same side as the orchiectomy. However, iliac radiotherapy is unnecessary in patients without prior inguinal or scrotal surgery. Furthermore, in recent years, other treatment modalities for this patient group have evolved. The use of single-agent carboplatin has shown promising results, similar to the effects obtained by radiotherapy. In addition, surveillance after primary orchiectomy with no additional treatment is found to be a safe follow-up for many of these patients. On the basis of new knowledge about primary tumour risk factors, it is now possible to identify patients at a particular high risk of relapse (rete testis invasion, primary tumour size > 4 cm, or both). This will be a helpful tool to identify patients who can be safely included into a surveillance strategy, and those who could have adjuvant treatment. The final decision about treatment will depend on risk factors, capacity of the healthcare service to carry out frequent follow-up examinations and the patient's own preferences. In this paper, we will discuss advantages and disadvantages of the various treatment options in the management of stage I seminoma.