en Original article Original article <span style="LINE-HEIGHT: 115% FONT-FAMILY: "Garamond","serif" FONT-SIZE: 10pt mso-bidi-font-family: 'Times New Roman' mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"><strong>Distinction between brucellar epididymo-orchitis (BEO) and nonspecific epididymo-orchitis (EO) is an important medical issue. This study was conducted to compare demographic, clinical and laboratory features, treatment and outcome of patients with BEO and nonspecific EO in Arak city, Markazi Province, Iran. We compared the clinical and laboratory characteristics of 40 BEO and 40 non-specific EO patients. The diagnosis of brucellosis was based on the symptoms, compatible clinical findings and standard tube agglutination test. Epididymo-orchitis was diagnosed by swelling and tenderness of scrotal skin, testis and epididymis, which was confirmed by sonography. BEO can be distinguished from nonspecific EO based on having a history of living in rural areas, contact with domestic animals, and consumption of unpasteurized dairy products. Other criteria include seasonal pattern, gradual onset (<i>P</i><0.05), sweating (<i>P</i><0.001), arthralgia (<i>P</i>=0.02), associated lower urinary tract symptoms (<i>P</i>=0.004) and lower rate of leukocytosis and abnormal urine analysis (<i>P</i>=0.002). Our results showed that brucellosis should be considered as a cause of EO in endemic areas like Iran. Combination antibiotic therapy to manage BEO is usually effective and all patients in this study responded quite satisfactory to the treatment. </strong></span> Brucellar epididymo-orchitis, Nonspecific epididymo-orchitis, Iran 8 13 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-25-7&slc_lang=en&sid=1 Masoomeh Sofian No Tuberculosis and Pediatric Infectious Research Center, Arak University of Medical Sciences, Arak, Iran Arezoo Aghakhani No Clinical Research Department, Pasteur Institute of Iran, Tehran, Iran Mohammad Banifazl No Iranian Society for Support of Patients with Infectious Disease, Tehran, Iran Ali Eslamifar No Clinical Research Department, Pasteur Institute of Iran, Tehran, Iran Fatemeh Zolfaghari No Tuberculosis and Pediatric Infectious Research Center, Arak University of Medical Sciences, Arak, Iran Hossein Sarmadian No Tuberculosis and Pediatric Infectious Research Center, Arak University of Medical Sciences, Arak, Iran Amitis Ramezani Yes Clinical Research Department, Pasteur Institute of Iran, Tehran, Iran