The design of a hammerhead bent cap is presented. The design is performed according to the ACI 318 Appendix A Strut-and-Tie Modeling (STM) provisions. The objective of this paper is to present a design example for designers who do not have a large amount of experience with strut-and-tie modeling. Strut-and-tie modeling is relatively new to ACI 318 as provisions were first included in the 2002 edition. The procedure may be used for the design of both reinforced and prestressed concrete structures. The following example is intended to supplement the basic example problems available in textbooks. For additional background information, a review of textbook-level material [ACI SP-208 (Reineck 2002); Schlaich et al. (1987)] is recommended.