Abstract: A horseshoe having adjustable flexibility 100 provides a body formed of left and right body portions 200, 300. In a preferred embodiment, forward ends of the body portions are connected by one of three or more alternative center pieces, each resulting in greater or lesser flexibility of the overall horseshoe. A rigid center piece 400 provides very little flexibility; a composite center piece 500 provides a greater degree of flexibility; and a flexible center piece 600 provides the greatest flexibility. The three may be easily interchanged. The horseshoe having adjustable flexibility 100 allows control over the degree to which a horse's hoof splays on impact, and other factors. A plurality of anti-splay flanges 700 allow control over the degree to which the hoof is allowed to splay or flex outwardly, by adjusting the rigidity of the connection to the horse's hoof. An elastic cross-member 800 may be attached between the rear end portions of the left and right body portions.