Ticks are known as a vector of many viral, bacterial, rickettsial and protozoan infections of dogs. The threat with particular tick-transmitted disease depends very much on the tick species which feeds on the dog. In this paper we present results of research designed to identify tick species which attack dogs in the Warsaw area. Ticks were collected from dogs presented for medical examination in veterinary clinics in different parts of Warsaw. All of 590 tick specimens found on dogs belonged to the family Ixodidae (hard ticks). The majority (64.6 %) of the collected ticks were identified as Dermacentor reticulatus--vector of Babesia canis. The other tick species found on examined dogs was Ixodes ricinus. The male to female ratio was more than 3 times higher in D. reticulatus than in I. ricinus.