Purpose: To evaluate the ultrasonographic features of nonlactiferous breast abscess. Materials and Methods: Weretrospectively reviewed ultrasonograms of 21 cases with surgically and clinically proved nonlactiferous breastabscess. The cases included 17 cases of acute or chronic inflammation and 4 cases of tuberculosis. Results:Location of the lesion was subareolar in 15 cases and peripheral in 6. Mean anteroposterior/transverse diameterratio was 0.49. Internal echogenicity of the lesion was varible, with heterogeneous mixed-echoic echotexture in 18cases and homogeneous hypoechoic in 3. The margin of the lesion was irregular in 18 cases(85.7%) and posteriorsonic enhancement was observed in 17 cases(81%). There were also noted obliteration of adjacent superficialfascia, localized skin thickening, and sinus tract or ductal ectasia in 19(90.5%), 9(42.9%), and 9(42.9%) casesrespectively. Conclusion: Major ultrasonographic findings of nonlatiferous breast abscess was subareolar located, variable shaped mass with posterior enhancement. Additional findings were fistular formation, loss of superficialfascia, and axillary lymphadenopathy.