Introduction and purpose: Fleas are ecto parasites of birds and mammals. In addition to causing harassment due to their bites, these insects transmit important diseases such as plague, endemic typhus and tularemia to humans. This study was conducted in order to identify the species and biodiversity of important medical fleas in Neka city, Mazandaran province. The present research is a descriptive-analytical study. 

  Methods: Sampling was done for one year from April to March 1401 in the rural areas of Neka city, Mazandaran province. In this study, 15 villages were randomly selected according to the geographic location of the north, south, east, west, and center.     Different methods were used to collect fleas including hand catch, human bait and spreading white cloth. The collected samples were preserved in closed tubes containing 70% alcohol and after clarifying and montage in the laboratory, they were identified using valid identification keys.

  Results: A total of 2600 fleas were caught in this study. Caught fleas included the species of Ctenocephalides canis (30.93%), Ctenocephalides felis (57.54%) and Pulex irritans (11.53%). Among the collected fleas, 33.12% were male and 66.89% were female. The dominant species among the caught fleas is Ctenocephalides felis, and the most collected fleas were from the village Estakhr Posht. In current study, the most caught fleas were related to the mountainous climate and in the spring season.

  Conclusion: The results of this research show that Ctenoscephalides felis is the dominant and most abundant species in Neka city, which can be considered as a health problem. Therefore, their presence and frequency should be considered seriously and appropriate control measures should be taken.