A case of right intrascrotal and seminal vesicular granuloma probably induced by Propionibacterium acnes is reported. A 62-year-old man was admitted to our department because of low grade fever and the right intrascrotal and retrovesical masses without tenderness. Ultrasonography computed tomography, magnetic resonance imaging and vesiculography suggested a neoplasm. However, leukocytosis and high erythrocyte sedimentation rate (ESR) and c-reactive protein level (CRP) suggested inflammatory disease. He was treated for 1 week with parenteral cefazolin (CEZ) (4 g/day), and the intrascrotal mass was remarkably reduced in size. To rule out neoplasms, right orchiectomy and needle biopsy of the right seminal vesicle were performed and nonspecific chronic granuloma was identified histologically. On the 5th postoperative day he developed fever (39.2 degrees C) and P. acnes was isolated from blood culture. Gram stain revealed gram-positive rods in the specimen. Further chemotherapy normalized levels of ESR and CRP and white blood cell count and reduced the right seminal vesicle to its normal size. Recently several cases of infection induced by P. acnes have been reported, but this is the first report in the genitourinary tract.