We present a case of allergic bronchopulmonary fusariosis (ABPF). This is the first case of allergic bronchopulmonary mycosis (ABPM) caused by Fusarium vasinfectum reported in the medical literature. The patient presented with a history and radiographic picture highly suggestive of allergic bronchopulmonary aspergillosis (ABPA), yet with negative ABPA serology results. The demonstration of a positive skin test and precipitins against F. vasinfectum, elevated serum IgG and IgE antibodies against F. vasinfectum, and a decline in total serum IgE with treatment clearly establish the diagnosis of ABPF. The diagnosis of ABPM caused by organisms other than Aspergillus represents an important consideration in patients who appear clinically to have ABPA but whose serology results do not confirm this diagnosis. As in ABPA, early diagnosis and appropriate therapy may be necessary in order to prevent progressive lung disease.