Follow-up bone scintigraphy (BS) in a patient of carcinoma left breast, who was treated with surgery followed by radiotherapy 12 years back, revealed asymmetrically increased radiotracer uptake in left-sided ribs. Since, this pattern was atypical for metastatic rib involvement, single photon emission computed tomography/computed tomography (SPECT/CT) of thorax was done in the same setting which revealed circumferential nodular left-sided pleural thickening. Biopsy confirmed it to be pleural mesothelioma. Left-sided ribs showed no abnormality on CT, thus suggesting the rib uptake as reactive in nature. This pattern of asymmetric rib uptake on BS should be kept in mind and warrants further investigation for determining underlying pathology.