The findings at scrotal sonography in 10 patients with tuberculous epididymitis and in 2 with nontuberculous epididymitis are presented. In 6 patients with tuberculous epididymitis the testes were also involved (epididymo-orchitis). The most notable sonographic findings of tuberculous epididymitis were an enlarged epididymis, predominantly in the tail portion, and marked heterogeneity of the echo texture of the involved epididymis. Sonographic findings of associated testicular involvement consisted of a diffusely enlarged hypoechoic testis or ill defined focal intratesticular hypoechoic areas, or an irregular margin between the testis and epididymis. The sonographic findings encountered in patients with tuberculous epididymitis appear to be different from those encountered in nontuberculous epididymitis. Sonography might prove helpful in aiding the clinical distinction between these 2 forms of epididymitis and in demonstrating associated testicular involvement in tuberculous epididymitis.