AbstractPurposeWhile scanning women for breast US, is possible to observe changes in the appearance of the pleural line or in the most superficial portion of the lung. The objective of this single‐center, prospective study was to determine the prevalence of a variety of pleural and pulmonary US findings during routine breast US.MethodsIn this study, there were 200 women undergoing standard breast US examination. The presence of pleural and pulmonary abnormalities in these cases was recorded. Two off‐site reviewers confirmed the presence of pleura and lung changes.ResultsThere was no abnormal finding in 168 out of 200 cases (84%) while there were one or more abnormal findings in 32 cases (16%). Pleural effusion was observed in 0.5% of cases, thickening of the pleural line 5% of cases, irregularity of the pleural line in 6% of cases, increased number of vertical artifacts in 9% of cases, subpleural nodulations in 2% of cases, and lung consolidation in 0.5%.ConclusionPleural and lung changes are not uncommon during breast US. Operators performing breast US examinations should be aware of the possibility to identify unsuspected pleuro‐pulmonary abnormalities.