Physical agents such as ultraviolet or ionizing radiation and repetitive trauma have been related to the causation of cancer in humans. Much less clear is the association between exposure to radiofrequency, such as radar and microwave radiation to the development of cancer. Sporadic case reports and small series suggest that this type of radiation might lead to cancer or contribute to its evolution. The association between radiofrequency and testicular damage and cancer is unproved, but clinical and experimental data are suggestive of such possibility. In this paper we have reported three cases of seminoma in person who worked in the same place that exposed to radio frequency (RF) waves.