Nivolumab is an immune checkpoint inhibitor (ICI) that has proven efficacy in managing certain malignancies, including non-small lung carcinoma. In this case, we present a 53-year-old female patient diagnosed with metastatic non-small lung carcinoma. After management with radiation (both external beam and brachytherapy) and tumor debulking by bronchoscopic cryotherapy, she developed an initial pneumonitis attributed to nivolumab and ipilimumab. This was successfully managed with steroid therapy and allowed nivolumab monotherapy to restart. However, several months later, she developed organizing pneumonia, prompting immunotherapy discontinuation and initiation of corticosteroid therapy. This case serves as a reminder to clinicians that although ICIs constitute a novel, effective therapy for certain malignancies, immunological side effects can be debilitating and prevent continued immunotherapy. Through this case, we aim to review the literature about this rare side effect of nivolumab-induced pneumonitis, risk factors, diagnosis, and management.