Human dirofilariasis is a disease which is considered to be rare in Greece, less than 20 cases having been reported prior to 1990. The clinical manifestations were usually subcutaneous nodules, and in only two cases there was ocular dirofilariasis. Eight new cases were recognized in humans during the last six years in Athens, two of which with ophthalmic involvement. Twelve additional cases have been detected but not published in Thessaloniki. In all human cases, the worms were identified as being Dirofilaria repens (D. conjunctivae). The identification was based on the morphological observations of the whole nematodes and on the histological sections of the subcutaneous nodules in the samples. Four different filarial nematodes (D. immitis, D. repens, Dipetalonema reconditum and D. grassii) were recovered from dogs. Infection of dogs with all types of filariae ranges from 12% to 37%. The high incidence of dirofilariasis in dogs is of great interest compared to the low incidence in humans. The occurrence of common host animals and insect vectors makes dirofilariasis a potential danger for public health.