We report a case of stage IE non-Hodgkin's lymphoma of the testis including the sonographic and magnetic resonance imaging (MRI) findings. A 68-year-old male noticed a painless swelling of his right scrotal contents. The serum alpha-fetoprotein and beta-HCG levels were within the normal ranges. Scrotal ultra-sonography revealed a hypoechoic lesion in the right testis. This tumor showed isointensity on T1-weighted imaging and also showed low intensity on T2-weighted imaging. A high orchiectomy was performed and the histological diagnosis was non-Hodgkin's lymphoma. Adjuvant chemotherapy (cyclophosphamide, doxorubicin, vincristine and predonisolone) was administered. At 6 months postoperatively, this patient shows no signs of recurrence.