We report a 63 year old white man admitted to our hospital because of fever, productive cough and a severe respiratory failure. Bronchoalveolar lavage revealed a positive microscopy for acid-fast bacilli and a four drug scheme for tuberculosis was initiated. There was no improvement in the patient's condition and mechanical ventilation was needed. A thorax CT scan disclosed images that suggested lipoid pneumonia (lower lobes involvement, hypodensity and negative sign in the angiogram). At this point the patient's relatives indicated that he was a long term user of paraffin oil for chronic constipation. Treatment with high doses of steroids was initiated and after whole lung lavage, mechanical respiratory assistance could be interrupted. We comment the association of this entity with lung infections produced by atypical mycobacteria.