Dirofilaria are long, thin parasitic roundworms that infect a variety of mammals. Infection is transmitted by mosquito bites. There are many species of Dirofilaria, but human infection is caused most commonly by three species, D. immitis, D. repens, and D. tenuis. There are also several documented reports of Dirofilaria infections worldwide including America, Europe, and Australia. Eosinophilic meningitis in human has also attributed to these filarial nematodes as etiological agent diagnosed by immunofluorescence and arthus hypersensitivity. Inclusively several clinical cases of human dirofilariasis, including 270 pulmonary cases have been reported up to the end of the second millennium.