A 33-year-old woman presented with a painless right breast lump of four weeks' duration. There were no symptoms such as fever or night sweats. Mammogram revealed an elliptical lesion in the retromammary region. Ultrasonography showed a hypoechoeic collection deep in the right breast. As the lesion was localised to the chest wall, computed tomography of the thorax was performed. This confirmed a fluid collection in the right anterior chest wall and also bilateral upper lobe consolidations, suggestive of pulmonary tuberculosis with an abscess in the anterior chest wall. Ultrasound-guided core needle biopsy confirmed a Mycobacterium tuberculosis infection. It is unusual for a tuberculous abscess of the chest wall to present as a painless breast lump. We also present a companion case of tuberculous mastitis to illustrate their distinct imaging features.