In the past 10 years, many developments have allowed us to understand more fully the natural history and routes of spread of testicular seminoma. The development of radiological tests such as CT scanning has allowed us to better assess the extent of disease. The availability of serum tumor markers AFP and beta HCG has facilitated the recognition of the presence of occult non-seminomatous elements. These developments plus the knowledge that seminoma is sensitive to cisplatin containing chemotherapy and that it is exquisitely sensitivity to radiation therapy resulted in further improvement in therapy. Overall we now expect 97 to 98% of patients will be cured of their disease. Currently, a number of issues in the management of seminoma remain controversial. These controversies however impact on very small proportion of patients with seminoma. Between 5 and 10% of patients have stage IID, III, or IV disease and 10 to 20% of these patients ie: 1 or 2% of the total population actually die from testicular seminoma. Thus it is for patients with advanced disease that we seek to define the nature of optimal chemotherapy, that is the most effective yet least toxic regimen. For those 1 or 2% of patients dying of seminoma we seek to identify prognostic factors to identify these patients and better treatments for them. Refinements in the application of radiation therapy for early stage disease, should allow some reduction in the morbidity of radiation without compromising control rates. Testicular seminoma its investigation and management, serves as a model for understanding other malignant processes and for orderly ways in which to refine the therapeutic ratio in the management of disease.