A heart valve annulus sizer is provided for measuring a valve to be fitted with an annuloplasty ring. The sizer may include a body having a peripheral portion defining an opening, at least one rib disposed within the opening and dividing the opening into at least a first opening and a second opening, and an anchor disposed on and projecting from the body. The sizer may include a length of suture connected to the body. The anchor may include an aperture adapted to receive the length of suture. A method of using the sizer is provided that includes grasping the sizer with an instrument and positioning the sizer adjacent to a valve into a position suitable to allow for measurement of the valve.