The painful bite of Pulex irritans; causes wound on the host body and is a vector for Bartonella bacteria species, which can cause trench fever, Rickettsia species, Rocky Mountain spotted fever and Mediterranean spotted fever. We conducted a study to find out the hosts, abundance, as well as the molecular characteristics of this flea species in Meshkin-Shahr County, Ardabil Province, northwest of Iran. After collecting fleas from different reservoir hosts and transferring them to the laboratory, identification was done using different morphological characters as well as the internal transcribed spacer1 (ITS1) molecular marker. This morphological study indicated that from the 1053 fleas, which were collected from 162 different animals, including cats and dogs, 74 specimens belonged to human flea, Pulex irritans. In addition, in molecular analysis showed a high sequence similarity (99.5%) with the P. irritans counterparts from Spain country and Zanjan of Iran available in GenBank. Pulex irritans species is an obligatory hematophagous ectoparasite of human and animals. Therefore, considering the relatively high frequency of this species on the body of cats and dogs, it is suggested to conduct more studies on its distribution and the possibility of being a vector of pathogens among these animals and human. The results of these studies will be used to compile and review the control programs of this vector.