An iterative three dimensional Boundary Element Method (BEM) is formulated to investigate partial cavitating flows around cylindrical bodies at various angles of attack and validation is pursued through comparison with other numerical models. Also, in this article the effect of angle of attack on two types of head (conical and blunt-head) is investigated. The results show that the effect of angle of attack on variation of cavity shape at blunt-head cylinder is more considerable. The need for a very short time (less than 10 min) to reach the desirable convergence and also proper accuracy in calculating the properties of cavitating flows are considerable advantages of this method. Also, in this research, the effect of the length of a cylindrical body on the cavity length has been investigated. The results confirm that if the length of the body is greater than 1.7 times the cavity length, the effects of the negative pressure behind the cylindrical body on the cavity length can be neglected.