Infection by Dirofilaria immitis is a rare cause of solitary pulmonary nodule. We describe the second case of transitory pulmonary nodule found by us in the course of a case-finding study, the third one reported in the literature. The detection of cases of transient pulmonary dirofilariotic nodules suggests that human infection is more prevalent than usually thought, and that this kind of manifestation is frequent in human dirofilariosis. Greater awareness is warranted in endemic areas.