Introduction: Diffuse pulmonary ossification was firstly described by Luschka in 1856. It has two distinct patterns with different clinical, radiological, and histological associations: nodular pulmonary ossification (NPO) and dendriform pulmonary ossification (DPO). Dendriform pulmonary ossification is described by the presence of branching metaplastic osseous spicules usually with bone marrow elements. Dendriform pulmonary ossification is described by the presence of branching metaplastic osseous spicules usually with bone marrow elements. Dendriform pulmonary ossification can occur as idiopathic or in association with chronic lung diseases. Idiopathic DPO is a rare entity and has association with chronic gastric acidity. Case Report: A 36-year-old gentleman, unknown to have any medical illness, was incidentally found to have bilateral diffuse high-density lung opacities during workup for back pain. The patient was asymptomatic. High resolution computed tomography (HRCT) of the chest showed bilateral ossified tiny branching opacities mainly involving the lower lobes. Histologically, the sections showed lung parenchyma with mature bone formation in the interstitial pulmonary spaces with fatty marrow in some of the bony spicules. Complementary upper gastrointestinal study was conducted confirming the presence of high-volume gastro-esophageal reflux. Conclusion: Dendriform pulmonary ossification is a rare entity that can cause serious complications such as respiratory failure. Thus, awareness of it as a differential diagnosis of chronic lung disease is necessary. More studies are needed to establish treatment guidelines and long-term prognosis.