Objective:To determine the tick species parasitizing domestic ruminants in Ghaemshahr county in Mazandaran,a Caspian province in the north of Iran.Methods:About 361 sheep, 54 goats and 10 cattle of 18 herds in several villages in Ghaemshahr were inspected for tick infestation.Separated ticks were preserved in 70% alcohol and identified.Results:About 323 ticks(207 female,116 male) were collected,the occurrence of ticks on sheep,goats and cattle were 28.3% .22.2% and 20.0% respectively.The mean number of ticks on each animal was low (3-5 ticks per animal).Rhipicephalus sanguineus,Rhipicephalus bursa.Ixodes ricinus,Boophilus annulalus,Haemaphysalis punctata and Haemaphysalis numidiana were the tick species we found.Rhipicephalus sanguineus were the most abundant species in the study area.The largest number of ticks were generally present from April to July,mostly in animal ears and tails. Ixodes,Boophilus and Haemaphysalis occurred in mountainous areas of Ghaemshahr.whereas Rhipicephalus were present in both mountains and plains of the study area.Conclusions:The result of this study is a survey of tick species from domestic animals in Iran and implication of possible prevention measures for diseases transmitted by ticks. Objective: To determine the tick species parasitizing domestic ruminants in Ghaemshahr county in Mazandaran, a Caspian province in the north of Iran. Methods: About 361 sheep, 54 goats and 10 cattle of 18 herds in several villages in Ghaemshahr were inspected for tick infestation. Separated ticks were preserved in 70% alcohol and identified. Results: About 323 ticks (207 female, 116 male) were collected, the occurrence of ticks on sheep, goats and cattle were 28.3% .22.2% and 20.0% respectively. The mean number of ticks on each animal was low (3-5 ticks per animal). Rhipicephalus sanguineus, Rhipicephalus bursa. Ixodes ricinus, Boophilus annulalus, Haemaphysalis punctata and Haemaphysalis numidiana were the tick species we found.Rhipicephalus sanguineus were the most abundant species in the study area.The largest number of ticks were generally present from April to July, mostly in animal ears and tails. Ixodes, Boophilus and Haemaphysalis occurred in mountainous areas of Ghaemshahr. whereas Rhipicephalus were present in both mountains and plains of the study area. Conclusions: The result of this study is a survey of tick species from domestic animals in Iran and implication of possible prevention measures for disease transmitted by ticks.