An adult female opossum (Didelphis virginiana) presented to Cornell University for progressive alopecia and weight loss. Physical examination revealed dehydration, emaciation, anemia, presumptive bite wounds, a digital degloving wound, diarrhea, diffuse alopecia, and mite infestation. Whole body radiographs showed variable interstitial to alveolar patterns in the lungs bilaterally. Her condition significantly improved after antibiotics, analgesics, B complex vitamins and subcutaneous fluid administration. Soon after, however, the patient’s health status declined and she developed signs of respiratory distress. A fecal analysis revealed thousands of Didelphostrongylus sp. larvae and further radiographs revealed pleural and peritoneal effusions. The patient was euthanized and submitted for necropsy. Significant pathologic findings included Didelphostrongylus hayesi associated atelectasis and multifocal granulomatous pneumonia, fibrinosuppurative pericarditis, congestive heart failure, gastrointestinal nematodiasis and cestodiasis. Although verminous pneumonias are not uncommon in Virginia opossums, the true significance of D. hayesi in the overall population has yet to be determined.