Wells' syndrome (WS) is a rare, recurrent, inflammatory dermatosis of uncertain pathogenesis, although a hypersensitivity response to different stimuli has been postulated. Several cases in association with parasitic infections have been described. We present a patient with WS associated with recurrent giardiasis. The course of the dermatosis was strictly related to the course of the parasitic infection. Both diseases disappeared with antiparasitic treatment. To our knowledge, this association is here reported for the first time.