In the Czech Republic, vector borne diseases - leishmaniosis, dirofilariosis, babesiosis and ehrlichiosis are classified as serious imported infections of dogs. In order to identify the risk of traveling and imported dogs to become infected we have examined a group of 97 (Group 1) dogs which were potentially at risk because they either traveled to or were imported from foreign countries endemic for these infections. The second group (Group 2) was set up from 80 non-traveling dogs living in areas of the Czech Republic with a potential risk of Dirofilaria immitis, D. repens, Babesia canis and Anaplasma phagocytophilum transmission. Vectors of these pathogens are commonly found in Czech Republic. The study was carried out from November 2003 to May 2006. For laboratory tests, samples of whole blood, blood serum and 2 fresh blood smears were obtained from each dog. As the vectors of leishmaniosis are not found in the Czech Republic, only dogs from the first group were examined. 10 (10.3%) out of 97 dogs from Group 1 examined for leishmaniosis were serologically positive using indirect hemagglutination test. Microscopical examination of stained smears from lymph node or bone marrow fine needle aspiration revealed the amastigotes of parasites in 7 dogs serologically positive the other three were free of amastigotes. Seven dogs, which were found positive during microscopical examination of lymph node aspiration, were suffering from serious clinical signs. The mosquito vectors of dirofilariosis are endemic in our country, so not only imported or traveling dogs (Group 1), but also dogs living only in the Czech Republic (Group 2) were examined. No animal out of a total of 97 dogs from Group 1 examined for dirofilariosis was positive. Seven animals (8.8%) out of a total of 80 dogs from Group 2 examined for dirofilariosis were positive. Acid phosphatase staining identified D. repens species in all the samples. PCR definitely confirmed D. repens diagnosis in these samples. 13 dogs (7.3%) out of 177 dogs examined for babesiosis were positive. All positive dogs were from the Group1. None of 80 dogs living in the area of the Czech Republic, where Dermacentor reticulatus ticks with a vector potential occur, was positive for babesiosis. Rhipicephalus sanguineus is a vector of E. canis which does not occur in the Czech Republic. None of the dogs (Group 1) examined for ehrlichiosis was positive. Intracellular morulae of Ehrlichia canis were not microscopically found and serologic tests (IFAT) were also negative in all animals. Ixodes ricinus transmits the agent of canine granulocytic ehrlichiosis/anaplasmosis - A. phagocytophilum in Europe. It is the most common tick in the Czech Republic. Only animals from the Group 1 were tested for A. phagocytophilum using both IFAT and microscopic examination. 8 (10%) out of 80 dogs examined for anaplasmosis were serologically positive. Intracellular morulae of A. phagocytophilum were not microscopically found. All positive animals showed serious clinical signs of the respective disease and were treated accordingly. From our data we conclude that exotic diseases of traveling dogs seem to be important emerging infections in our country which veterinary practitioners must deal with. Methods of diagnosis, treatment and prevention must be discussed to avoid increasing risk of these infections in new regions.