Nodular fasciitis of the breast is a rare, benign, soft-tissue tumor that can clinically and radiologically mimic invasive ductal carcinoma. A 25-year-old woman presented with a palpable lesion in the lower inner aspect of the left breast. Radiologically, breast carcinoma could not be excluded. On examination of the core needle biopsy, the tumor was characterized histologically as a spindle cell tumor. Excisional biopsy was performed. The tumor was diagnosed as nodular fasciitis of the breast. The imaging and histological findings of this case are presented.