U.S. service members are at increased risk of Strongyloides stercoralis infection, due to their potential for occupational soil exposure in endemic tropical and sub-tropical areas. Infection is mainly acquired by the filariform larvae penetrating the skin and can be sustained for decades through autoinfection. A life-threatening hyperinfection syndrome is possible during times of immunosuppression. Strongyloides stercoralis risk factors include being stationed in, or emigrating from, endemic areas and are important considerations for Military Health System (MHS) medical providers. We present a case of a Vietnam War veteran in his 70s with a history of chronic obstructive pulmonary disease, non-small cell lung cancer stage IIa, and prostate cancer who presented to the emergency department of a military treatment facility for shortness of breath and cough. He was initially treated as an outpatient for community acquired pneumonia but ultimately required admission. Eosinophilia was noted and an expanded evaluation was conducted, during which he was found to be seropositive for Strongyloides stercoralis. The patient was treated for strongyloidiasis with a standard 2 day course of ivermectin because he was at a heightened risk for hyperinfection syndrome and sepsis. He then continued regular care for his underlying conditions. Our review of his medical record revealed multiple prior opportunities where clinical signs coupled with his military service history should have prompted diagnostic testing or empiric therapy for strongyloidiasis. Over the preceding 9 years, he had three periods of documented eosinophilia for which strongyloidiasis was never considered or tested for. In addition to his chemotherapy treatment, he received 11 courses of systemic steroids over the time period, with at least one meeting dosage criteria sufficient to suppress the immune system.