We present the case of a microscopic polyangiitis (MPA) patient who developed strongyloidiasis, nocardia and citrobacter freundii (CF) infection after corticosteroides and immunosuppressant therapy. When digestive, respiratory or other system symptoms consecutively occur in a immunocompromised host who lives in tropical or temperate zone and have close contact with soil, we should take strongyloidiasis into consideration despite absence of eosinophilia. Mixed infection with nocardia cannot be easily excluded. It is essential to search for the etiology proof with multiple approaches positively and repeatedly.