As a consequence of viscous flow characteristics in the vicinity of a flying body, thermal stresses generate heating of the body. In some cases, when these thermal stresses become significantly high, body wall temperature reaches high enough values to cause failure of wall material, or at least, damage of on-board equipment. In such cases thermal protection becomes a vital precautionary measure. This paper illustrates the various thermal protection techniques commonly used with missiles. Focus is made on a widely used technique namely, ablative thermal protection. A complete calculation procedure was developed for the evaluation of shield effectiveness and ablative thickness for a conical forebody. A computer code was developed as a tool for easy, fast, and accurate calculation of shield thickness and the net wall temperature distribution along a conical forebody during a complete flight at zero incidence. The code was applied to a number of real missiles with a variety of flight conditions, results were confirmed.