ABSTRACT: gallstones are common diseases in many countries of the world , and incidence rate may reach about 20 % .Most cases of gallstones occur in females , the incidence rate may reach four times to one in comparison between women and men , mainly in fatty , fertile , age of forty female , gall stones are rare before age of 20 years ,but; may occur at any age . many cases are not diagnosed because they do not cause any signs or symptoms , and thus can only be diagnosed accidently by routine abdominal ultrasound. The aim of study is to evaluate the relationship between age,sex and body mass index as risk factors for gallstone. a cross sectional study was conducted in Tikrit city during the period from early of May to the end of October 2019 . 468 were enrolled in present study , and only 95 patients were diagnosed as a case of gallstone (29 male , 66 female). All patients attending private ultrasound clinic with different complains, data was collected by using certain questionnaire. The results showed that, There was highly significant statistical relationship (P – value ≤0.05) between body mass index mean in both gallstone cases(26.628±5.808) and, in cases without gallstone(22.225±1.316). In the present study there was high statistically significant relation(P- value ≤ 0.05) between body mass index measurement above 25(31.97727273± 3.747859149) and measurement below 25(21.85882353± 1.616313889) in patients with gallstone. The present study conclude that , Body mass index more than 25 considered as an important risk factor for gallstone.