Osimertinib is an oral epithelial growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) used primarily in the treatment of metastatic non-small cell lung cancer. It is usually well tolerated with less than 5% of patients developing significant pulmonary toxicity from the medication, typically within the first few months after initiation. Previously reported pulmonary adverse reactions include pneumonitis (nonspecific interstitial pneumonia or other forms of acute interstitial process), fleeting asymptomatic infiltrates on imaging, and eosinophilic pneumonia. We present an interesting case of a 65-year-old female with recurrent metastatic adenocarcinoma of the lung, treated with Osimertinib for 4 months, who developed a previously unreported toxicity of diffuse alveolar hemorrhage (DAH) requiring mechanical ventilatory support.